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Original Article |

Functional NPY Variation as a Factor in Stress Resilience and Alcohol Consumption in Rhesus Macaques FREE

Stephen G. Lindell, MS; Melanie L. Schwandt, PhD; Hui Sun, PhD; Jeffrey D. Sparenborg, BS; Karl Björk, PhD; John W. Kasckow, MD, PhD; Wolfgang H. Sommer, MD, PhD; David Goldman, MD; J. Dee Higley, PhD; Stephen J. Suomi, PhD; Markus Heilig, MD, PhD; Christina S. Barr, VMD, PhD
[+] Author Affiliations

Author Affiliations: Laboratories of Clinical and Translational Studies (Mssrs Lindell and Sparenborg, and Drs Schwandt, Sun, Björk, Sommer, Heilig, and Barr) and Neurogenetics (Dr Goldman), National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland; Western Psychiatric Institute and Clinics, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Kasckow); Department of Psychology, Brigham Young University, Provo, Utah (Dr Higley); and Laboratory of Comparative Ethology, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Poolesville, Maryland (Dr Suomi).


Arch Gen Psychiatry. 2010;67(4):423-431. doi:10.1001/archgenpsychiatry.2010.23.
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Context  Neuropeptide Y (NPY) counters stress and is involved in neuroadaptations that drive escalated alcohol drinking in rodents. In humans, low NPY expression predicts amygdala response and emotional reactivity. Genetic variation that affects the NPY system could moderate stress resilience and susceptibility to alcohol dependence.

Objective  To determine whether functional NPY variation influences behavioral adaptation to stress and alcohol consumption in a nonhuman primate model of early adversity (peer rearing).

Design  We sequenced the rhesus macaque NPY locus (rhNPY) and performed in silico analysis to identify functional variants. We performed gel shift assays using nuclear extract from testes, brain, and hypothalamus. Levels of NPY in cerebrospinal fluid were measured by radioimmunoassay, and messenger RNA levels were assessed in the amygdala using real-time polymerase chain reaction. Animals were exposed to repeated social separation stress and tested for individual differences in alcohol consumption. Animals were genotyped for −1002 T > G, and the data were analyzed using analysis of variance.

Setting  National Institutes of Health Animal Center.

Subjects  Ninety-six rhesus macaques.

Main Outcome Measure  Behavior arousal during social separation stress and ethanol consumption.

Results  The G allele altered binding of regulatory proteins in all nuclear extracts tested, and −1002 T > G resulted in lower levels of NPY expression in the amygdala. Macaques exposed to adversity had lower cerebrospinal fluid NPY levels and exhibited higher levels of arousal during stress, but only as a function of the G allele. We also found that stress-exposed G allele carriers consumed more alcohol and exhibited an escalation in intake over cycles of alcohol availability and deprivation.

Conclusions  Our results suggest a role for NPY promoter variation in the susceptibility to alcohol use disorders and point to NPY as a candidate for examining gene × environment interactions in humans.

Figures in this Article

Exposure to adversity is known to increase an individual's risk of developing stress-related conditions, such as anxiety, depression, and addictive disorders, including alcohol dependence.1,2 A number of studies have shown that genetic variants that increase anxiety interact with stressful events to impart risk of these disorders.3,4 Functional genetic variation that reduces stress resiliency would be equally likely to moderate risk. The neuropeptide Y (NPY) system is one whose regulation mediates stress adaptation and is therefore a candidate system in which functional genetic variation may affect resilience. In response to protracted or repeated periods of stress, NPY is released in key regions of the brain, a mechanism proposed to be important for countering effects of stress.5 Individuals who differ in the ability to recruit this system would be expected to differ in resilience and thus vulnerability to stress-related disorders.

Studies indicate that stress exposure early in life is particularly likely to induce adult psychopathology.6 The rhesus macaque model has led the way as a controlled experimental system that permits examination of how early adversity in the form of maternal deprivation interacts with functional genetic variants to influence stress reactivity and alcohol consumption.7 Infants that are reared with age mates and not by their mothers (peer-reared), show evidence of harm avoidance, insecure attachment, and high levels of anxiety.8,9 In addition to exhibiting these life-long traits, peer-reared monkeys consume higher levels of alcohol.10,11 Whether NPY variation influences these phenotypes in primates has not yet been demonstrated.

Prolonged exposure to alcohol leads to sensitization of behavioral stress responses and escalated alcohol intake. These neuroadaptations are in large part mediated through recruitment of corticotropin-releasing hormone (CRH, or corticotropin-releasing factor [CRF]) signaling within the amygdala complex.5 Under these conditions, rodent studies have shown that both exogenous NPY administration and overexpression of Npy in the amygdala reduce stress responses and suppress excessive alcohol intake.12,13 Whether induced by genetic selection for alcohol preference14,15 or neuroadaptations encompassing stress circuitry,12 the emerging role of NPY is as a negative regulator of excessive alcohol consumption. It may be that NPY could negatively regulate alcohol intake induced by other environmental stressors that recruit the CRF system. We predicted that NPY variation would modulate stress reactivity and alcohol intake, particularly as a function of prior stress or alcohol exposure.

Functional variants in the macaque are of particular interest because several key mediators of stress responses, such as CRF, are differentially distributed between rodents and primates and also because several rhesus variants that are functionally equivalent to those in humans have been identified.1619 The existence of these variants and the demonstrated feasibility of modeling early adversity in the rhesus macaque combine to provide a unique opportunity for studies of gene × environment interactions that may be relevant for humans.3,7,20 Here, we examined whether rhesus NPY (rhNPY) variation influenced stress resiliency and voluntary alcohol consumption. We screened rhNPY and regulatory regions for variation and investigated the functionality of a single-nucleotide polymorphism (SNP; rhNPY −1002 T>G), located in a region that is orthologous to one demonstrated to be important for regulation of human NPY promoter activity.21 Because of the role of the NPY system in stress and alcohol response, we examined whether −1002 T > G influenced behavioral arousal during social separation stress and voluntary alcohol consumption. Finally, because the NPY system becomes involved in neuroadaptations that drive escalated alcohol drinking, we also examined whether rhNPY −1002 T/G genotype differentially influenced alcohol intake over cycles of alcohol availability and deprivation.

IDENTIFICATION OF NPY SEQUENCE VARIANTS

Genomic DNA was extracted from whole blood from rhesus macaques (Macaca mulatta) from the National Institutes of Health Animal Center, and direct sequencing was performed using samples from 96 unrelated animals (pairwise identity by descent ≤0.0125). We used primers designed from a published human sequence and rhesus sequence (http://genome.ucsc.edu/cgi-bin/hgGateway) to sequence 2.5 kilobases of the 5′ regulatory region, exons 1 through 4 (exon 1 = 5′ untranslated region, exon 2 = NPY, exon 3 = C-terminal flanking peptide of NPY, and exon 4 = 3′ untranslated region), intron 1, and the exon-intron boundaries. Cycle sequencing was performed using the Big Dye Terminator, version 3.1, reaction in 96-well optical plates (Applied Biosystems, Foster City, California). Variants were detected by visualization of electropherograms generated by ABI Sequencing Analysis software.

To identify putatively functional variants, we examined regions containing consensus sites for factors known to regulate NPY transcription21,22 and used Web-based transcription factor binding site prediction algorithms (TfSitescan, http://www.ifti.org/cgi-bin/ifti/Tfsitescan.pl23 and TFSEARCH, http://www.cbrc.jp/research/db/TFSEARCH.html24). Comparative genomic analyses across anthropoid primates (Homo sapiens, Pan troglodytes, Pongo pygmaeus, M mulatta, and Callithrix jacchus) were performed using the University of California–Santa Cruz Genome Browser (http://genome.ucsc.edu/cgi-bin/hgGateway).

ELECTROPHORETIC MOBILITY SHIFT ASSAY

Based on the identification of a putatively functional variant (−1002 T > G) within the rhNPY regulatory region, double-stranded oligonucleotides containing the T (5′-GCA AAT TAA TGTTCA TCG TTT TTA ACA TG-3′) and G (5′-GCA AAT TAA TGTGCA TCG TTT TTA ACA TG-5′) alleles were used to perform gel shift assays using nuclear extract from the human whole brain, the osteosarcoma cell line, MG-63 (both from ActivMotif, Carlsbad, California), and from an immortalized glucocorticoid-treated hypothalamic cell line (IVB cells treated with 100nM dexamethasone).25 Assays were performed using the Gel Shift Assay System (Promega, Madison, Wisconsin) according to the manufacturer's instructions. After annealing complementary oligonucleotides (at 95°C for 5 minutes and at 25°C for 30 minutes), double-stranded probes were labeled with [32P]–adenosine triphosphate using T4 kinase (Promega) and purified using a Bio-Spin 30 chromatography column (Bio-Rad Laboratories, Hercules, California). Incorporation of the radiolabel was greater than 1 × 105–cpm/ng DNA. Binding assays were performed using the Gel Shift Assay System (Promega) according to the manufacturer's instructions. Nuclear extracts (5 μg/assay) were incubated for 20 minutes with 1 × 105 cpm of each oligonucleotide probe. Competitor oligonucleotides were added at 10 times the concentration of the labeled probes. Samples were immediately separated by electrophoresis (300 V for 20 minutes) at 4°C on a Novex 6% DNA retardation gel along with prestained protein molecular weight standards (Invitrogen, Carlsbad). Each gel shift assay was performed in duplicate.

Acute stress regulates Npy expression in the rat hypothalamus, and the temporal dynamics of this regulation are similar to those observed in other regions of the brain.26 Given that the −1002 T > G SNP disrupts a putative glucocorticoid response element, we wanted to determine whether we would observe glucocorticoid-dependent differences in the patterns of DNA-protein interactions and whether these differed according to genotype. To examine this, we performed gel supershift assays using an anti–glucocorticoid receptor antibody (Santa Cruz Biotechnology, Santa Cruz, California) with the glucocorticoid receptor–enriched MG-63 nuclear extract. The nuclear extract (1 μL) and antibody (1 μL) were preincubated for 30 minutes at 25°C prior to performance of the assay.

NPY MESSENGER RNA QUANTIFICATION BY REAL-TIME POLYMERASE CHAIN REACTION

RNA was extracted from rhesus amygdalae using Trizol according to the manufacturer's protocol (Invitrogen). Prior to complementary DNA synthesis, RNA cleanup was performed using the RNeasy Mini Kit (Qiagen, Germantown, Maryland), and RNA was treated with RQ1 RNase-free DNase (Promega) following the manufacturer's instructions. Total RNA quality and integrity were verified by optical density measurements (260 nm/280 nm) and by measuring ribosomal 28S:18S ratios using RNA 6000 230 Nano Assay RNA chips run on an Agilent 2100 Bioanalyzer (Agilent Technologies, Palo Alto, California). RNA (100 ng) was then used for complementary DNA synthesis, applying reverse-transcription reagents (Applied Biosystems).

NPY expression in the amygdala (n = 12) was assessed by real-time polymerase chain reaction. Applied Biosystems assay Rh02787751_m1 was used to detect NPY messenger RNA. β-Actin expression was used as an endogenous reference (Applied Biosystems No. Hs99999903_m1). Samples were analyzed in quadruplicate on an ABI Prism 7900HT system with Taqman universal polymerase chain reaction master mix. The amplification conditions were 50°C for 2 minutes and then 95°C for 10 minutes, followed by 40 cycles at 95°C for 15 seconds and 60°C for 1 minute. The SDS 2.0 software (Applied Biosystems) was used to analyze and convert the expression data into cycle threshold values (Ct values). Data are expressed as relative NPY messenger RNA levels normalized to the −1002T/T group.

PHYSIOLOGIC AND BEHAVIOR ASSESSMENTS OF EXPERIMENTAL ANIMALS
Rearing

Rhesus macaque (M mulatta) infants at the National Institutes of Health Animal Center were randomly selected to be reared with their mothers or in a nursery by human caregivers.10,27,28 Mother-reared animals were reared in social groups composed of 8 to 14 females (about half of which had same-aged infants) and 2 adult males. Peer-reared animals were separated from their mothers at birth and hand-reared in a neonatal nursery for the first 37 days of life. For the first 14 days, they were kept in an incubator and hand fed. From day 15 until day 37, they were placed alone in a nursery cage and provided a blanket and a terry cloth–covered rocking surrogate. A bottle from which the infants would feed was fixed to the surrogate. At 37 days of age, peer-reared infants were placed in a cage with 3 other age mates with whom they had continuous contact. Mother-reared infants remained in their social group. At approximately 8 months of age, both peer-reared and mother-reared animals were placed together in age-matched social groups and housed in large indoor-outdoor runs through late adolescence, at which point the cohorts were divided into same-sex groups. All procedures were approved by the National Institute on Alcohol Abuse and Alcoholism and The Eunice Kennedy Shriver National Institute of Child Health and Human Development Animal Care and Use Committee.

Cerebrospinal Fluid Sampling and Radioimmunoassay

Cerebrospinal fluid (CSF) levels of NPY were assessed in late adolescent and young adult animals prior to alcohol exposure to determine whether rhNPY −1002 T > G was associated with differences in central NPY release. The CSF samples were obtained from the cisterna cerebellomedullaris posterior using a 5-mL syringe with a 22-gauge needle while the animal was under ketamine anesthesia (15 mg/kg, intramuscularly). All samples were collected within 30 minutes of investigators' entering the area in which the animals were housed. The CSF samples were immediately aliquoted into polypropylene tubes, frozen in liquid nitrogen, and stored at −70°C until assay using a commercially available kit (Bachem/Peninsula Laboratories, San Carlos, California). The between- and within-assay coefficients of variation were less than 10%.

Social Separation Stress

Separation stress was used because of the known effects of separation in this highly social species and because we wanted to look at the effects of protracted stress, which would be impossible to achieve with, for example, immobilization. When animals reached 6 months of age, they were subjected to 4 sequential, 4-day separations.28 Subjects in the peer group were partitioned into individual sections of the home cage, which prevented the infants from seeing or touching one another. Mother-reared infants were separated from their mothers by removing the mother from the social group. Day 1 (Monday) of each separation week was designated as the acute phase of separation. Days 2 through 4 (Tuesday-Thursday) of each separation week were designated as chronic separation. Following each separation week, subjects were reunited with their attachment sources early on Friday morning and separated again at noon on Monday.

During each separation week, a total of 9 behavioral observations were made, according to the following schedule (for behavior definitions, see eTable 1). Three observations were made on day one: 2 immediately following separation and 1 at hour 1 (acute). Two observations were made each day for days 2 through 4 (chronic). Each observation period was 300 seconds. Behavioral data were collected by multiple observers, with an interobserver reliability of 85% or more.

Alcohol Consumption

Nine cohorts of young adult macaques (age, 3.5-5.0 years) were allowed to freely consume an aspartame-sweetened (8.4% vol/vol) alcohol solution for 1 hour per day, 5 days a week in the home cage. This method consisted of 3 phases, which have previously been reported29: (1) spout training, (2) initial alcohol exposure, and (3) an experimental period. During the experimental phase, the alcohol and vehicle were dispensed 5 days a week (Monday-Friday) from 1 to 2 PM while the animals were in their home cage environment.

GENOTYPING

A portion of the rhNPY regulatory region (−1216 > −671) was amplified from 25 ng of genomic DNA with flanking oligonucleotides (5′-TGC TTT AAT TTC CCA ACA TGC; 5′-GGA GAG TAC TTG AGG AAG GCT G) in 15-μL reactions using an AmpliTaq Gold DNA Polymerase LD (low DNA) kit from Applied Biosystems. Amplifications were performed on a thermocycler (9700; Applied Biosystems) with 1 cycle at 96°C for 5 minutes followed by 30 cycles at 94°C for 15 seconds, 60°C for 15 seconds, and 72°C for 30 seconds, and a final 3-minute extension at 72°C. Amplicons were sequenced using the Big Dye Terminator, version 3.1, kit and the 3100 Genetic Analyzer (Applied Biosystems). Genotypes were called by direct visualization of electropherograms using 4Peaks (http://www.mekentosj.com).

STATISTICAL ANALYSIS

We used archived data sets to examine the effects of NPY −1002 T > G on our phenotypes of interest. Most animals included in these data sets underwent other procedures prior to the time of social separation (primate neonatal neurobehavioral assessment,30,31 n = 88; developmental CSF sampling,32 n = 119). There were also subjects that underwent neuroimaging (positron-emission tomography and single-photon emission computed tomography, n = 20)3335 or intravenous alcohol infusion (n = 92)36 prior to alcohol testing.

Behavioral scores during separation stress exposure were averaged for each phase (acute and chronic) across the 4 weeks of testing. Scores for each behavior were expressed as the mean frequency or duration of the behavior for the 2 testing conditions (acute and chronic stress). As scores of behaviors relating to stress responding were intercorrelated, we performed factor analysis to reduce the dimensionality of the data. Separate factor analyses for both phases of separation were performed using principal components extraction and varimax orthogonal rotation. Factors indicative of high levels of attachment (separation anxiety), stereotypy (behavioral pathology), and arousal were identified. Although NPY has not been linked to social attachment or stereotypies, it has been repeatedly demonstrated to influence levels of arousal.3739 To avoid uninformative, repeated testing, we therefore focused on effects of the rhNPY −1002 T > G genotype on arousal.3739 We performed 2-way analysis of variance on acute and chronic arousal, with genotype (T/T, T/G, and G/G) and rearing condition (peer-reared vs mother-reared) as nominal independent variables. Two-way analysis of variance was also performed to assess effects of rearing and genotype on CSF NPY and voluntary alcohol consumption. Under a limited access schedule, we have determined that alcohol consumption increases following a 3-day period of deprivation (0.3-1.0 g/kg/h) (eFigure 1), suggesting there is an alcohol-deprivation effect. To examine whether genotype interacted with periods of alcohol deprivation (5 days of 1-hour access with 3 days of deprivation) to influence the pattern of alcohol consumption across time, we used a mixed-design repeated-measures analysis of variance to examine the effects of genotype and rearing on alcohol consumption using data obtained on the first day of access (Monday) during the 4 weeks of testing. All post hoc comparisons were made using the Tukey-Kramer method.

The frequency of the G allele was 37%, and genotype frequencies were in Hardy-Weinberg equilibrium. Although this is an outbred colony of macaques, to verify that our effects were attributable to rhNPY variation and not to general heritability of our traits of interest, we repeated our analyses using a set of 3 biallelic genetic markers with similar minor allele frequencies to the −1002 G allele (15%-35% as carriers; OPRM1 C77G and SNPs in the DAT and CRH promoters).40,41 Similar effects of the other markers tested on phenotypes of interest were not observed, supporting the argument that our current results are attributable to effects of NPY −1002 T > G. We also excluded animals that carried alleles known to interact with early peer rearing to predict our phenotypes of interest (ie, rh5-HTT-LPR s allele); as results were unchanged, these animals (n = 20) were included in the final analyses. The Kolmogorov-Smirnov normality test and equality of variances F test were used to determine whether data deviated from normality and whether there was nonhomogeneity of the data. In cases in which there was nonnormality or inequality of variances, data were rank-transformed and the analyses repeated. Analyses were performed using StatView, version 5.01, statistical software. Significance was set at P ≤ .05.

IDENTIFICATION OF A FUNCTIONAL VARIANT IN THE rhNPY PROMOTER

We sequenced the rhNPY gene, first intron, exon-intron boundaries, and 3′ and 5′ flanking regions and identified 12 polymorphic sites (Figure 1A). Variants were assigned positions relative to the transcription start site. In silico analysis indicated that a SNP (−1002 T > G) present in a region orthologous to one shown to be important to regulation of NPY transcriptional control21 predicted the loss of a glucocorticoid response element half-site (Figure 1B). We found that the T > G SNP resulted in altered binding of regulatory proteins, with several bands increasing (molecular weight of approximately 130, 210, and 260 kDa) and 1 of 180 kDa showing a relative decrease (Figure 1C). We also found that, in the amygdala, the G allele resulted in decreased levels of NPY expression (Figure 1D) (F1,9 = 24.4, P <.001). We performed gel supershift assays using an anti–glucocorticoid receptor antibody and found that the T allele showed a relative increase in the degree of binding of the 180-kDa (and 90-kDa) bands, both of which showed decreased motility with the addition of the anti–glucocorticoid receptor antibody. The 180-kDa band (glucocorticoid receptor dimer) was preferentially bound in experiments performed with T allele oligonucleotides (eFigure 2).

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Figure 1.

Rhesus NPY −1002 T > G is present in a conserved portion of an NPY repressor and results in altered DNA-protein interactions and decreased amygdala NPY expression. A, A schematic of NPY, regulatory region, and single-nucleotide polymorphisms (SNPs) detected by sequencing of genomic DNA. B, Region 40 base pairs upstream and downstream of the −1002 T > G SNP. The precise locations of the −1002 T > G SNP (in bold) and the oligonucleotide sequence used in the gel shift assays (underlined) are indicated. Predicted sites for transcription factor binding (above) and sequence conservation among primates (below, black indicates conserved) are shown. Binding sites (shown in dashed lines; Sox5 and a preferred glucocorticoid response element half-site) were predicted to be disrupted by the −1002 T > G SNP. C, Gel shift assay results from experiments performed using nuclear extracts from whole-brain tissue, osteosarcoma cells (MG-63), and glucocorticoid-treated hypothalamic cells (IVB cells treated with dexamethasone [IVB + Dex]). Relative migrations of the protein molecular weight standards are shown. Open arrowheads indicate bands that increase with G allele probes, and closed arrowheads indicate that which shows a relative increase with T allele probes. D, NPY messenger RNA (mRNA) expression in the amygdala as a function of the −1002 T > G allele (P < .001; T/T, n = 4; G carrier, n = 8). *P < .001. kb indicates kilobase.

Graphic Jump Location
CSF NPY

There was a trend for an effect of rearing condition, with lower NPY levels among peer-reared animals (F2,66 = 2.68, P = .1). There was no main effect for genotype (F2,66 = 0.84, P = .44). However, genotype interacted with rearing condition to predict CSF NPY (F2,66 = 4.2, P = .02). Peer-reared animals carrying the G allele (T/G or G/G) had lower CSF NPY levels than did peer-reared T/T animals (Tukey-Kramer, P < .05) (Figure 2). Among peer-reared subjects, genotype accounted for 28% of the variance.

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Figure 2.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on cerebrospinal fluid (CSF) levels of neuropeptide Y (NPY). There was an interaction between genotype and rearing (F2,66 = 4.2, P = .02). The G allele decreased levels of NPY in a dose-dependent manner measured in a cisternal CSF sample among stress-exposed monkeys (mother-reared T/T, n = 17; mother-reared T/G, n = 14; mother-reared G/G, n = 4; peer-reared T/T, n = 16; peer-reared T/G, n = 13; and peer-reared G/G, n = 8) (Tukey-Kramer, P < .05). Genotype accounted for 28% of the variance in peer-reared subjects. Error bars indicate standard error of the mean; *P < .05.

Graphic Jump Location
BEHAVIORAL RESPONSES TO STRESS

Factor analysis performed on behavioral measures recorded during social separation generated 3 factors for each of the 2 phases of data collection. For the acute phase of stress, 3 factors (separation anxiety, arousal, and behavioral pathology) accounted for 71.6% of the variance. The same 3 factors accounted for 77.6% of the variance for analysis performed on behaviors collected during chronic separation stress (eTable 2).

During acute separation, there were main effects of rearing (F1,96 = 6.4, P = .01) and genotype (F2,96 = 3.2, P = .04) on arousal, but no interaction. Post hoc analyses demonstrated that peer-reared infants exhibited higher levels of arousal than mother-reared infants and that those homozygous for the G allele had higher arousal scores than those homozygous for the T allele (Tukey-Kramer, P < .05) (Figure 3A). As with acute stress exposure, there was a main effect of rearing condition on arousal (F1,96 = 25.0, P < .001) during chronic separation, with peer-reared animals exhibiting higher scores (Tukey-Kramer, P < .05) (Figure 3B). There was no main effect for genotype. However, there was an interaction between rearing and genotype (F2,96 = 4.2, P = .02). Although peer-reared T/T subjects responded no differently than mother-reared animals, peer-reared G allele carriers (T/G or G/G) exhibited higher levels of arousal (Tukey-Kramer, P < .05) (Figure 3B). In both cases (acute and chronic stress), results remained the same following rank transformation of the data. Among peer-reared subjects, genotype accounted for 7% and 10% of the variance during acute and chronic stress exposure, respectively.

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Figure 3.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on arousal during periods of acute (1 hour) and chronic (96 hours) separation stress. A, During acute separation stress, there were main effects of both rearing (F1,96 = 6.4, P = .01) and genotype (F2,96 = 3.2, P = .04) on arousal, with genotype accounting for 7% of the variance. B, During chronic stress, there was an interaction between rearing and genotype (F2,96 = 4.2, P = .02). Although peer-reared T/T subjects responded no differently than mother-reared animals, peer-reared G allele carriers exhibited higher levels of arousal (T/G and G/G vs T/T, Tukey-Kramer, P < .05), with genotype accounting for 10% of the variance in these subjects (mother-reared T/T, n = 35; mother-reared T/G, n = 27; mother-reared G/G, n = 10; peer-reared T/T, n = 9; peer-reared T/G, n = 15; and peer-reared G/G, n = 6). Error bars indicate standard error of the mean; *P < .05.

Graphic Jump Location
ALCOHOL CONSUMPTION

There was a main effect of rearing condition on alcohol, with peer-reared consuming more alcohol than mother-reared subjects (F1,85 = 16.5, P < .001). There was also an interaction between rearing and genotype (F2,85 = 3.3, P = .04), and this relationship remained following rank transformation of the data. Among peer-reared monkeys, only carriers of the G allele (T/G and G/G) consumed higher levels of alcohol than mother-reared monkeys (Tukey-Kramer, P < .05) (Figure 4). Genotype accounted for 12.5% of the variance in alcohol consumption in peer-reared subjects.

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Figure 4.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on levels of voluntary alcohol consumption. There was an interaction between rearing condition and genotype on alcohol consumption (F2,85 = 3.3, P = .04). When given simultaneous access to alcohol (8.4% vol/vol) in a sweetened vehicle in a limited access paradigm, peer-reared monkeys who were carriers of the G allele consumed higher levels of alcohol than did non–stress-exposed (mother-reared) subjects (Tukey-Kramer, P < .05). Genotype accounted for 12.5% of the variance in peer-reared monkeys (mother-reared T/T, n = 29; mother-reared T/G, n = 25; mother-reared G/G, n = 8; peer-reared T/T, n = 10; peer-reared T/G, n = 11; peer-reared G/G, n = 8). Error bars indicate standard error of the mean; *P < .05.

Graphic Jump Location

When we examined effects of rearing and genotype on alcohol consumption following periods of deprivation across the 4 weeks of testing, we found a main effect of rearing (F1,204 = 12.5, P < .001). There were also different temporal courses of consumption during successive weeks as a function of genotype and rearing (genotype × time interaction, F6,204 = 3.02, P = .008; rearing × genotype × time interaction, F6,204 = 2.2, P = .04) (Figure 5). When we examined the effects of genotype, rearing, and time across weeks of testing during the second through fifth days for the weekly sessions, the effects of genotype (F2,228 = 3.23, P = .04), rearing (F1,228 = 26.4, P < .001), and genotype × rearing interaction (F2,228 = 4.9, P = .01) were maintained, but there were not interactions of any of these factors with week of testing (eFigure 3).

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Figure 5.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on alcohol consumption across repeated weeks of alcohol deprivation (weeks 1, 2, 3, and 4). There were both genotype × time (F6,204 = 3.02, P = .008) and genotype × time × rearing (F6,204 = 2.2, P = .04) interactions. In peer-reared monkeys, alcohol intake decreased over time in those with the T/T genotype, but an escalation in consumption was observed in those carrying the G allele. There was no significant effect of genotype in mother-reared monkeys. The interaction between time and genotype accounted for 19% of the variance in peer-reared monkeys (mother-reared T/T, n = 22; mother-reared T/G, n = 19; mother-reared G/G, n = 7; peer-reared T/T, n = 9; peer-reared T/G, n = 10; and peer-reared G/G, n = 7). Values shown are the amount of alcohol consumed in a 1-hour session after a 3-day period of deprivation. Error bars indicate standard error of the mean.

Graphic Jump Location

There is accumulating evidence that genetic and environmental factors interact to determine susceptibility to stress-related disorders later in life.3 Of particular interest for the study of gene × environment interactions is variation in genes encoding stress-responsive–signaling molecules that may contribute to stress vulnerability or resiliency.7 Perhaps most notable among the gene × environment studies are those examining interactions between life stress and the serotonin transporter-linked polymorphism (5-HTTLPR). We have previously demonstrated that a functionally similar variant in rhesus macaques, rh5-HTTLPR, interacts with early adversity in the form of peer rearing to influence stress reactivity and alcohol consumption, emphasizing the utility of the peer-rearing model for examining gene × environment interactions that translate to the human condition.

Because the NPY system is a key mediator of behavioral adaptation to stress, we screened the rhNPY gene for variants that might affect stress resilience, with the prediction that we would observe similar interactions. We identified a SNP (−1002 T > G) in the rhNPY regulatory region that predicts loss of a glucocorticoid response element half-site. Glucocorticoids have long been known to regulate NPY expression,42 and this regulation may be important for stress-mediated NPY induction. We performed gel shift assays with nuclear extract derived from several glucocorticoid receptor–expressing cell lines42,43 and found that the G allele resulted in altered DNA-protein interactions. Among the bands that exhibited a relative decrease with the G allele (which, overall, showed increased transcription factor binding) was one measuring 180 kDa, which was recognized by an anti–glucocorticoid receptor antibody. This suggests that the −1002 T > G SNP resulted in decreased preference for a functional glucocorticoid response element. We found that −1002 T > G predicted decreased NPY expression in the amygdala, a brain region in which NPY release decreases anxious responding. Based on these functional differences, we predicted that this SNP would result in decreased NPY system activity and/or a failure to recruit the NPY system under stressful conditions, both of which could lead to reduced stress resiliency.

In humans, both genetic and environmental factors are suggested to influence NPY system function. Decreases in NPY levels are observed among subjects with treatment-refractory depression and posttraumatic stress disorder.4447 There is also evidence that a gain-of-function variant resulting in a Leu7Pro substitution of the prepro-NPY signal peptide47 may protect against depression, while markers on low-expressing NPY haplotypes (−399 T > C) result in decreased NPY levels and upregulated stress responses.46,48 Herein, we showed that rhesus macaques exposed to adversity have lower CSF levels of NPY, but only as a function of the loss-of-function G allele. Although it is also conceivable that social separation could represent a different experience for mother-reared and peer-reared animals, consistent with our CSF NPY result, peer-reared G allele carriers are more aroused during both short-term and protracted exposures to social separation stress. We postulate that a history of trauma and genotype may also interact to predict NPY levels in humans and that individuals with low levels of NPY expression or who are less capable of recruiting the NPY system in response to stress would be less stress resilient and therefore more vulnerable to stress-related disorders.

There is considerable evidence suggesting that NPY regulates alcohol consumption.4951Npy-deficient mice consume more ethanol, while consumption is reduced in mice overexpressing Npy.51 Moreover, Npy maps to a quantitative trait locus underlying alcohol consumption in genetically selected alcohol-preferring rats.52 Based on these findings, a screen for functional variants was performed, identifying a marker (D4Mit7) that reduced brain expression of Npy in this line.53 In humans, linkage to the chromosomal region containing NPY has been demonstrated,54 and there have been associations of NPY variation with both alcohol consumption47 and dependence.55,56 Other studies, however, have failed to replicate this association.5759 Of note, our present study did not find any effects of rhNPY −1002 T > G on alcohol consumption in normally reared animals, even following repeated alcohol exposure. Instead, rhNPY −1002 T > G genotype increased alcohol consumption among those exposed to both early adversity and cycles of alcohol exposure. This suggests that a high degree of stress loading—or environmental stress/deprivation during critical developmental windows—may be required for the G allele to produce an effect, raising the possibility that human NPY variation could potentially increase risk of alcohol dependence more so among individuals with especially traumatic life experiences and early or high cumulative levels of stress exposure. In support of this argument, the only reports of a link between NPY variation and alcohol dependence have studied individuals with late-onset alcoholism56 or samples highly represented by war veterans.57

Dysregulation of the CRF system following repeated periods of alcohol exposure and deprivations contributes to the transition from reward to relief drinking,5,60 and NPY signaling is a counterregulatory process that buffers actions of CRF.5 When we examined patterns of alcohol intake during repeated cycles of availability and deprivation, we found an interaction between NPY genotype and alcohol exposure, such that stress-exposed G allele carriers exhibit a pattern of escalated alcohol intake. This is potentially indicative of a genotype-mediated inability to recruit NPY in response to induction of the CRF system among subjects consuming high levels of alcohol, suggesting that these subjects might more easily transition to the addicted state.

The NPY system is important to countering stress. We hypothesized that genetic variation that resulted in low levels of NPY expression or a failure to recruit the NPY system would render individuals less resilient to stress and to addiction with continued alcohol use. Studies in humans have demonstrated there to be haplotypes that decrease NPY expression and predict stress-induced NPY release, amygdala response, and stress resiliency.48 However, whether NPY promoter variation moderates risk of alcohol problems or interacts with life stress to moderate risk of stress-related psychiatric disorders has not been determined. Using an established primate model of adversity, we found that functional NPY variation influences CSF levels of NPY, behavioral arousal in response to stress, and alcohol consumption. Overall, this study suggests a role for NPY variation in the susceptibility to alcohol-related disorders and may further implicate this system as a treatment target in selected individuals. Our results also suggest NPY to be a candidate for examining gene × environment interactions in humans.

Correspondence: Christina S. Barr, VMD, PhD, Laboratory of Clinical Studies, Primate Section, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, PO Box 529, Poolesville, MD 20837 (cbarr@mail.nih.gov).

Submitted for Publication: October 30, 2008; final revision received August 18, 2009; accepted August 20, 2009.

Author Contributions: Drs Higley, Suomi, Heilig, and Barr contributed equally to this work.

Financial Disclosure: Dr Kasckow has been awarded a research grant from Astra Zeneca to study quetiapine in older patients with schizophrenia; and he is analyzing data from a National Institutes of Mental Health study that was completed 2 years ago, for which part of the medication was provided by Forest Pharmaceuticals.

Funding/Support: This work was funded by the National Institute on Alcohol Abuse and Alcoholism, the Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Programs, and NARSAD.

Previous Presentations: This study was presented as a talk and a poster at the annual meeting of the American College of Neuropsychopharmacology; Scottsdale, Arizona; December 6-11, 2008.

Additional Contributions: Karen Smith, MLS, assisted in the preparation of the manuscript, and the research and animal care staff at the National Institutes of Health Animal Center assisted in data collection.

De Bellis  MD Developmental traumatology: a contributory mechanism for alcohol and substance use disorders. Psychoneuroendocrinology 2002;27 (1-2) 155- 170
PubMed Link to Article
Reed  PLAnthony  JCBreslau  N Incidence of drug problems in young adults exposed to trauma and posttraumatic stress disorder: do early life experiences and predispositions matter? Arch Gen Psychiatry 2007;64 (12) 1435- 1442
PubMed Link to Article
Caspi  AMoffitt  TE Gene-environment interactions in psychiatry: joining forces with neuroscience. Nat Rev Neurosci 2006;7 (7) 583- 590
PubMed Link to Article
Koenen  KCNugent  NRAmstadter  AB Gene-environment interaction in posttraumatic stress disorder: review, strategy and new directions for future research. Eur Arch Psychiatry Clin Neurosci 2008;258 (2) 82- 96
PubMed Link to Article
Heilig  MKoob  GF A key role for corticotropin-releasing factor in alcohol dependence. Trends Neurosci 2007;30 (8) 399- 406
PubMed Link to Article
Weber  KRockstroh  BBorgelt  JAwiszus  BPopov  THoffmann  KSchonauer  KWatzl  HPropster  K Stress load during childhood affects psychopathology in psychiatric patients. BMC Psychiatry 2008;863
PubMed Link to Article
Barr  CSGoldman  D Non-human primate models of inheritance vulnerability to alcohol use disorders. Addict Biol 2006;11 (3-4) 374- 385
PubMed Link to Article
Suomi  SJ The development of social competence by rhesus monkeys. Ann Ist Super Sanita 1982;18 (2) 193- 202
PubMed
Ruppenthal  GCArling  GLHarlow  HFSackett  GPSuomi  SJ A 10-year perspective of motherless-mother monkey behavior. J Abnorm Psychol 1976;85 (4) 341- 349
PubMed Link to Article
Higley  JDHasert  MFSuomi  SJLinnoila  M Nonhuman primate model of alcohol abuse: effects of early experience, personality, and stress on alcohol consumption. Proc Natl Acad Sci U S A 1991;88 (16) 7261- 7265
PubMed Link to Article
Suomi  SJCollins  MLHarlow  HFRuppenthal  GC Effects of maternal and peer separations on young monkeys. J Child Psychol Psychiatry 1976;17 (2) 101- 112
PubMed Link to Article
Thorsell  ARepunte-Canonigo  VO'Dell  LEChen  SAKing  ARLekic  DKoob  GFSanna  PP Viral vector-induced amygdala NPY overexpression reverses increased alcohol intake caused by repeated deprivations in Wistar rats. Brain 2007;130 (pt 5) 1330- 1337
PubMed Link to Article
Gilpin  NWStewart  RBBadia-Elder  NE Neuropeptide Y suppresses ethanol drinking in ethanol-abstinent, but not non–ethanol-abstinent, Wistar rats. Alcohol 2008;42 (7) 541- 551
PubMed Link to Article
Badia-Elder  NEStewart  RBPowrozek  TARoy  KFMurphy  JMLi  TK Effect of neuropeptide Y (NPY) on oral ethanol intake in Wistar, alcohol-preferring (P), and -nonpreferring (NP) rats. Alcohol Clin Exp Res 2001;25 (3) 386- 390
PubMed Link to Article
Badia-Elder  NEStewart  RBPowrozek  TAMurphy  JMLi  TK Effects of neuropeptide Y on sucrose and ethanol intake and on anxiety-like behavior in high alcohol drinking (HAD) and low alcohol drinking (LAD) rats. Alcohol Clin Exp Res 2003;27 (6) 894- 899
PubMed Link to Article
Bennett  AJLesch  KPHeils  ALong  JCLorenz  JGShoaf  SEChampoux  MSuomi  SJLinnoila  MVHigley  JD Early experience and serotonin transporter gene variation interact to influence primate CNS function. Mol Psychiatry 2002;7 (1) 118- 122
PubMed Link to Article
Newman  TKSyagailo  YVBarr  CSWendland  JRChampoux  MGraessle  MSuomi  SJHigley  JDLesch  KP Monoamine oxidase A gene promoter variation and rearing experience influences aggressive behavior in rhesus monkeys. Biol Psychiatry 2005;57 (2) 167- 172
PubMed Link to Article
Barr  CSDvoskin  RLYuan  QLipsky  RHGupte  MHu  XZhou  ZSchwandt  MLLindell  SG McKee  MBecker  MLKling  MAGold  PWHigley  DHeilig  MSuomi  SJGoldman  D CRH haplotype as a factor influencing cerebrospinal fluid levels of corticotropin-releasing hormone, hypothalamic-pituitary-adrenal axis activity, temperament, and alcohol consumption in rhesus macaques. Arch Gen Psychiatry 2008;65 (8) 934- 944
PubMed Link to Article
Miller  GMBendor  JTiefenbacher  SYang  HNovak  MAMadras  BK A mu-opioid receptor single nucleotide polymorphism in rhesus monkey: association with stress response and aggression. Mol Psychiatry 2004;9 (1) 99- 108
PubMed Link to Article
Barr  CSSchwandt  MLNewman  TKHigley  JD The use of adolescent nonhuman primates to model human alcohol intake: neurobiological, genetic, and psychological variables. Ann N Y Acad Sci 2004;1021221- 233
PubMed Link to Article
Mayer  CMCai  FCui  HGillespie  JMMacMillan  MBelsham  DD Analysis of a repressor region in the human neuropeptide Y gene that binds Oct-1 and Pbx-1 in GT1-7 neurons. Biochem Biophys Res Commun 2003;307 (4) 847- 854
PubMed Link to Article
Higuchi  HNakano  KMiki  N Identification of NGF-response element in the rat neuropeptide Y gene and induction of the binding proteins. Biochem Biophys Res Commun 1992;189 (3) 1553- 1560
PubMed Link to Article
Kel-Margoulis  OVKel  AEReuter  IDeineko  IVWingender  E TRANSCompel: a database on composite regulatory elements in eukaryotic genes. Nucleic Acids Res 2002;30 (1) 332- 334
PubMed Link to Article
Heinemeyer  TWingender  EReuter  IHermjakob  HKel  AEKel  OVIgnatieva  EVAnanko  EAPodkolodnaya  OAKolpakov  FAPodkolodny  NLKolchanov  NA Databases on transcriptional regulation: TRANSFAC, TRRD and COMPEL. Nucleic Acids Res 1998;26 (1) 362- 367
PubMed Link to Article
Kasckow  JMulchahey  JJAguilera  GPisarska  MNikodemova  MChen  HCHerman  JPMurphy  EKLiu  YRizvi  TADautzenberg  FMSheriff  S Corticotropin-releasing hormone (CRH) expression and protein kinase A mediated CRH receptor signaling in an immortalized hypothalamic cell line. J Neuroendocrinol 2003;15 (5) 521- 529
PubMed Link to Article
Kim  HWhang  WWKim  HTPyun  KHCho  SYHahm  DHLee  HJShim  I Expression of neuropeptide Y and cholecystokinin in the rat brain by chronic mild stress. Brain Res 2003;983 (1-2) 201- 208
PubMed Link to Article
Higley  JDSuomi  SJLinnoila  M A nonhuman primate model of type II excessive alcohol consumption, 1: low cerebrospinal fluid 5-hydroxyindoleacetic acid concentrations and diminished social competence correlate with excessive alcohol consumption. Alcohol Clin Exp Res 1996;20 (4) 629- 642
PubMed Link to Article
Higley  JDSuomi  SJLinnoila  M CSF monoamine metabolite concentrations vary according to age, rearing, and sex, and are influenced by the stressor of social separation in rhesus monkeys. Psychopharmacology (Berl) 1991;103 (4) 551- 556
PubMed Link to Article
Barr  CSNewman  TKLindell  SShannon  CChampoux  MLesch  KPSuomi  SJGoldman  DHigley  JD Interaction between serotonin transporter gene variation and rearing condition in alcohol preference and consumption in female primates. Arch Gen Psychiatry 2004;61 (11) 1146- 1152
PubMed Link to Article
Schneider  MLMoore  CFSuomi  SJChampoux  M Laboratory assessment of temperament and environmental enrichment in rhesus monkey infants (Macaca mulatta). Am J Primatol 1991;25 (3) 137- 155
Link to Article
Champoux  MBennett  AShannon  CHigley  JDLesch  KPSuomi  SJ Serotonin transporter gene polymorphism, differential early rearing, and behavior in rhesus monkey neonates. Mol Psychiatry 2002;7 (10) 1058- 1063
PubMed Link to Article
Shannon  CSchwandt  MLChampoux  MShoaf  SESuomi  SJLinnoila  MHigley  JD Maternal absence and stability of individual differences in CSF 5-HIAA concentrations in rhesus monkey infants. Am J Psychiatry 2005;162 (9) 1658- 1664
PubMed Link to Article
Shoaf  SECarson  RHommer  DWilliams  WHigley  JDSchmall  BHerscovitch  PEckelman  WLinnoila  M Brain serotonin synthesis rates in rhesus monkeys determined by [11C]alpha-methyl-L-tryptophan and positron emission tomography compared to CSF 5-hydroxyindole-3-acetic acid concentrations. Neuropsychopharmacology 1998;19 (5) 345- 353
PubMed Link to Article
Ichise  MVines  DCGura  TAnderson  GMSuomi  SJHigley  JDInnis  RB Effects of early life stress on [11C]DASB positron emission tomography imaging of serotonin transporters in adolescent peer- and mother-reared rhesus monkeys. J Neurosci 2006;26 (17) 4638- 4643
PubMed Link to Article
Heinz  AHigley  JDGorey  JGSaunders  RCJones  DWHommer  DZajicek  KSuomi  SJLesch  KPWeinberger  DRLinnoila  M In vivo association between alcohol intoxication, aggression, and serotonin transporter availability in nonhuman primates. Am J Psychiatry 1998;155 (8) 1023- 1028
PubMed
Barr  CSSchwandt  MLindell  SGChen  SAGoldman  DSuomi  SJHigley  JDHeilig  M Association of a functional polymorphism in the mu-opioid receptor gene with alcohol response and consumption in male rhesus macaques. Arch Gen Psychiatry 2007;64 (3) 369- 376
PubMed Link to Article
Korotkova  TMBrown  RESergeeva  OAPonomarenko  AAHaas  HL Effects of arousal- and feeding-related neuropeptides on dopaminergic and GABAergic neurons in the ventral tegmental area of the rat. Eur J Neurosci 2006;23 (10) 2677- 2685
PubMed Link to Article
Fu  LYAcuna-Goycolea  Cvan den Pol  AN Neuropeptide Y inhibits hypocretin/orexin neurons by multiple presynaptic and postsynaptic mechanisms: tonic depression of the hypothalamic arousal system. J Neurosci 2004;24 (40) 8741- 8751
PubMed Link to Article
Karlsson  RMChoe  JSCameron  HAThorsell  ACrawley  JNHolmes  AHeilig  M The neuropeptide Y Y1 receptor subtype is necessary for the anxiolytic-like effects of neuropeptide Y, but not the antidepressant-like effects of fluoxetine in mice. Psychopharmacology (Berl) 2008;195 (4) 547- 557
PubMed Link to Article
Barr  CSNewman  TKSchwandt  MShannon  CDvoskin  RLLindell  SGTaubman  JThompson  BChampoux  MLesch  KPGoldman  DSuomi  SJHigley  JD Sexual dichotomy of an interaction between early adversity and the serotonin transporter gene promoter variant in rhesus macaques. Proc Natl Acad Sci U S A 2004;101 (33) 12358- 12363
PubMed Link to Article
Barr  CSSchwandt  MLLindell  SGHigley  JDMaestripieri  DGoldman  DSuomi  SJHeilig  M Variation at the mu-opioid receptor gene (OPRM1) influences attachment behavior in infant primates. Proc Natl Acad Sci U S A 2008;105 (13) 5277- 5281
PubMed Link to Article
Higuchi  HYang  HYSabol  SL Rat neuropeptide Y precursor gene expression. mRNA structure, tissue distribution, and regulation by glucocorticoids, cyclic AMP, and phorbol ester. J Biol Chem 1988;263 (13) 6288- 6295
PubMed
Wenger  TBouhdiba  MSaint Pol  PCiofi  PTramu  GLeonardelli  J Presence of neuropeptide–Y and its C-terminal flanking peptide immuno-reactivity in the seminiferous tubules of human testis. Andrologia 1990;22 (4) 299- 303
PubMed Link to Article
Morgan  CA  IIIWang  SSouthwick  SMRasmusson  AHazlett  GHauger  RLCharney  DS Plasma neuropeptide-Y concentrations in humans exposed to military survival training. Biol Psychiatry 2000;47 (10) 902- 909
PubMed Link to Article
Yehuda  RBrand  SYang  RK Plasma neuropeptide Y concentrations in combat exposed veterans: relationship to trauma exposure, recovery from PTSD, and coping. Biol Psychiatry 2006;59 (7) 660- 663
PubMed Link to Article
Heilig  MZachrisson  OThorsell  AEhnvall  AMottagui-Tabar  SSjogren  MAsberg  MEkman  RWahlestedt  CAgren  H Decreased cerebrospinal fluid neuropeptide Y (NPY) in patients with treatment refractory unipolar major depression: preliminary evidence for association with preproNPY gene polymorphism. J Psychiatr Res 2004;38 (2) 113- 121
PubMed Link to Article
Karvonen  MKPesonen  UKoulu  MNiskanen  LLaakso  MRissanen  ADekker  JMHart  LMValve  RUusitupa  MIJ Association of a leucine(7)-to-proline(7) polymorphism in the signal peptide of neuropeptide Y with high serum cholesterol and LDL cholesterol levels. Nat Med 1998;4 (12) 1434- 1437
PubMed Link to Article
Zhou  ZZhu  GHariri  AREnoch  MAScott  DSinha  RVirkkunen  MMash  DCLipsky  RHHu  XZHodgkinson  CAXu  KBuzas  BYuan  QShen  PHFerrell  REManuck  SBBrown  SMHauger  RLStohler  CSZubieta  JKGoldman  D Genetic variation in human NPY expression affects stress response and emotion. Nature 2008;452 (7190) 997- 1001
PubMed Link to Article
Ehlers  CLLi  TKLumeng  LHwang  BHSomes  CJimenez  PMathe  AA Neuropeptide Y levels in ethanol-naive alcohol-preferring and nonpreferring rats and in Wistar rats after ethanol exposure. Alcohol Clin Exp Res 1998;22 (8) 1778- 1782
PubMed Link to Article
Tecott  LHHeberlein  U Y do we drink? Cell 1998;95 (6) 733- 735
PubMed Link to Article
Thiele  TEMarsh  DJSte Marie  LBernstein  ILPalmiter  RD Ethanol consumption and resistance are inversely related to neuropeptide Y levels. Nature 1998;396 (6709) 366- 369
PubMed Link to Article
Carr  LGForoud  TBice  PGobbett  TIvashina  JEdenberg  HLumeng  LLi  TK A quantitative trait locus for alcohol consumption in selectively bred rat lines. Alcohol Clin Exp Res 1998;22 (4) 884- 887
PubMed Link to Article
Spence  JPLiang  THabegger  KCarr  LG Effect of polymorphism on expression of the neuropeptide Y gene in inbred alcohol-preferring and -nonpreferring rats. Neuroscience 2005;131 (4) 871- 876
PubMed Link to Article
Reich  TEdenberg  HJGoate  AWilliams  JTRice  JPVan Eerdewegh  PForoud  THesselbrock  VSchuckit  MABucholz  KKPorjesz  BLi  TKConneally  PMNurnberger  JIJ  JrTischfield  JACrowe  RRCloninger  CRWu  WShears  SCarr  KCrose  CWillig  CBegleiter  H Genome-wide search for genes affecting the risk for alcohol dependence. Am J Med Genet 1998;81 (3) 207- 215
PubMed Link to Article
Lappalainen  JKranzler  HRMalison  RPrice  LHVan Dyck  CRosenheck  RACramer  JSouthwick  SCharney  DKrystal  JGelernter  J A functional neuropeptide Y Leu7Pro polymorphism associated with alcohol dependence in a large population sample from the United States. Arch Gen Psychiatry 2002;59 (9) 825- 831
PubMed Link to Article
Mottagui-Tabar  SPrince  JAWahlestedt  CZhu  GGoldman  DHeilig  M A novel single nucleotide polymorphism of the neuropeptide Y (NPY) gene associated with alcohol dependence. Alcohol Clin Exp Res 2005;29 (5) 702- 707
PubMed Link to Article
Zhu  GPollak  LMottagui-Tabar  SWahlestedt  CTaubman  JVirkkunen  MGoldman  DHeilig  M NPY leu7pro and alcohol dependence in Finnish and Swedish populations. Alcohol Clin Exp Res 2003;27 (1) 19- 24
PubMed Link to Article
Zill  PPreuss  UWKoller  GBondy  BSoyka  M Analysis of single nucleotide polymorphisms and haplotypes in the neuropeptide Y gene: no evidence for association with alcoholism in a German population sample. Alcohol Clin Exp Res 2008;32 (3) 430- 434
PubMed Link to Article
Wetherill  LSchuckit  MAHesselbrock  VXuei  XLiang  TDick  DMKramer  JNurnberger  JI  JrTischfield  JAPorjesz  BEdenberg  HJForoud  T Neuropeptide Y receptor genes are associated with alcohol dependence, alcohol withdrawal phenotypes, and cocaine dependence. Alcohol Clin Exp Res 2008;32 (12) 2031- 2040
PubMed Link to Article
Valdez  GRKoob  GF Allostasis and dysregulation of corticotropin-releasing factor and neuropeptide Y systems: implications for the development of alcoholism. Pharmacol Biochem Behav 2004;79 (4) 671- 689
PubMed Link to Article

Figures

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Figure 1.

Rhesus NPY −1002 T > G is present in a conserved portion of an NPY repressor and results in altered DNA-protein interactions and decreased amygdala NPY expression. A, A schematic of NPY, regulatory region, and single-nucleotide polymorphisms (SNPs) detected by sequencing of genomic DNA. B, Region 40 base pairs upstream and downstream of the −1002 T > G SNP. The precise locations of the −1002 T > G SNP (in bold) and the oligonucleotide sequence used in the gel shift assays (underlined) are indicated. Predicted sites for transcription factor binding (above) and sequence conservation among primates (below, black indicates conserved) are shown. Binding sites (shown in dashed lines; Sox5 and a preferred glucocorticoid response element half-site) were predicted to be disrupted by the −1002 T > G SNP. C, Gel shift assay results from experiments performed using nuclear extracts from whole-brain tissue, osteosarcoma cells (MG-63), and glucocorticoid-treated hypothalamic cells (IVB cells treated with dexamethasone [IVB + Dex]). Relative migrations of the protein molecular weight standards are shown. Open arrowheads indicate bands that increase with G allele probes, and closed arrowheads indicate that which shows a relative increase with T allele probes. D, NPY messenger RNA (mRNA) expression in the amygdala as a function of the −1002 T > G allele (P < .001; T/T, n = 4; G carrier, n = 8). *P < .001. kb indicates kilobase.

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Figure 2.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on cerebrospinal fluid (CSF) levels of neuropeptide Y (NPY). There was an interaction between genotype and rearing (F2,66 = 4.2, P = .02). The G allele decreased levels of NPY in a dose-dependent manner measured in a cisternal CSF sample among stress-exposed monkeys (mother-reared T/T, n = 17; mother-reared T/G, n = 14; mother-reared G/G, n = 4; peer-reared T/T, n = 16; peer-reared T/G, n = 13; and peer-reared G/G, n = 8) (Tukey-Kramer, P < .05). Genotype accounted for 28% of the variance in peer-reared subjects. Error bars indicate standard error of the mean; *P < .05.

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Figure 3.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on arousal during periods of acute (1 hour) and chronic (96 hours) separation stress. A, During acute separation stress, there were main effects of both rearing (F1,96 = 6.4, P = .01) and genotype (F2,96 = 3.2, P = .04) on arousal, with genotype accounting for 7% of the variance. B, During chronic stress, there was an interaction between rearing and genotype (F2,96 = 4.2, P = .02). Although peer-reared T/T subjects responded no differently than mother-reared animals, peer-reared G allele carriers exhibited higher levels of arousal (T/G and G/G vs T/T, Tukey-Kramer, P < .05), with genotype accounting for 10% of the variance in these subjects (mother-reared T/T, n = 35; mother-reared T/G, n = 27; mother-reared G/G, n = 10; peer-reared T/T, n = 9; peer-reared T/G, n = 15; and peer-reared G/G, n = 6). Error bars indicate standard error of the mean; *P < .05.

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Figure 4.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on levels of voluntary alcohol consumption. There was an interaction between rearing condition and genotype on alcohol consumption (F2,85 = 3.3, P = .04). When given simultaneous access to alcohol (8.4% vol/vol) in a sweetened vehicle in a limited access paradigm, peer-reared monkeys who were carriers of the G allele consumed higher levels of alcohol than did non–stress-exposed (mother-reared) subjects (Tukey-Kramer, P < .05). Genotype accounted for 12.5% of the variance in peer-reared monkeys (mother-reared T/T, n = 29; mother-reared T/G, n = 25; mother-reared G/G, n = 8; peer-reared T/T, n = 10; peer-reared T/G, n = 11; peer-reared G/G, n = 8). Error bars indicate standard error of the mean; *P < .05.

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Figure 5.

Interaction between rhesus NPY genotype (T/T, T/G, and G/G) and early rearing history on alcohol consumption across repeated weeks of alcohol deprivation (weeks 1, 2, 3, and 4). There were both genotype × time (F6,204 = 3.02, P = .008) and genotype × time × rearing (F6,204 = 2.2, P = .04) interactions. In peer-reared monkeys, alcohol intake decreased over time in those with the T/T genotype, but an escalation in consumption was observed in those carrying the G allele. There was no significant effect of genotype in mother-reared monkeys. The interaction between time and genotype accounted for 19% of the variance in peer-reared monkeys (mother-reared T/T, n = 22; mother-reared T/G, n = 19; mother-reared G/G, n = 7; peer-reared T/T, n = 9; peer-reared T/G, n = 10; and peer-reared G/G, n = 7). Values shown are the amount of alcohol consumed in a 1-hour session after a 3-day period of deprivation. Error bars indicate standard error of the mean.

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Tables

References

De Bellis  MD Developmental traumatology: a contributory mechanism for alcohol and substance use disorders. Psychoneuroendocrinology 2002;27 (1-2) 155- 170
PubMed Link to Article
Reed  PLAnthony  JCBreslau  N Incidence of drug problems in young adults exposed to trauma and posttraumatic stress disorder: do early life experiences and predispositions matter? Arch Gen Psychiatry 2007;64 (12) 1435- 1442
PubMed Link to Article
Caspi  AMoffitt  TE Gene-environment interactions in psychiatry: joining forces with neuroscience. Nat Rev Neurosci 2006;7 (7) 583- 590
PubMed Link to Article
Koenen  KCNugent  NRAmstadter  AB Gene-environment interaction in posttraumatic stress disorder: review, strategy and new directions for future research. Eur Arch Psychiatry Clin Neurosci 2008;258 (2) 82- 96
PubMed Link to Article
Heilig  MKoob  GF A key role for corticotropin-releasing factor in alcohol dependence. Trends Neurosci 2007;30 (8) 399- 406
PubMed Link to Article
Weber  KRockstroh  BBorgelt  JAwiszus  BPopov  THoffmann  KSchonauer  KWatzl  HPropster  K Stress load during childhood affects psychopathology in psychiatric patients. BMC Psychiatry 2008;863
PubMed Link to Article
Barr  CSGoldman  D Non-human primate models of inheritance vulnerability to alcohol use disorders. Addict Biol 2006;11 (3-4) 374- 385
PubMed Link to Article
Suomi  SJ The development of social competence by rhesus monkeys. Ann Ist Super Sanita 1982;18 (2) 193- 202
PubMed
Ruppenthal  GCArling  GLHarlow  HFSackett  GPSuomi  SJ A 10-year perspective of motherless-mother monkey behavior. J Abnorm Psychol 1976;85 (4) 341- 349
PubMed Link to Article
Higley  JDHasert  MFSuomi  SJLinnoila  M Nonhuman primate model of alcohol abuse: effects of early experience, personality, and stress on alcohol consumption. Proc Natl Acad Sci U S A 1991;88 (16) 7261- 7265
PubMed Link to Article
Suomi  SJCollins  MLHarlow  HFRuppenthal  GC Effects of maternal and peer separations on young monkeys. J Child Psychol Psychiatry 1976;17 (2) 101- 112
PubMed Link to Article
Thorsell  ARepunte-Canonigo  VO'Dell  LEChen  SAKing  ARLekic  DKoob  GFSanna  PP Viral vector-induced amygdala NPY overexpression reverses increased alcohol intake caused by repeated deprivations in Wistar rats. Brain 2007;130 (pt 5) 1330- 1337
PubMed Link to Article
Gilpin  NWStewart  RBBadia-Elder  NE Neuropeptide Y suppresses ethanol drinking in ethanol-abstinent, but not non–ethanol-abstinent, Wistar rats. Alcohol 2008;42 (7) 541- 551
PubMed Link to Article
Badia-Elder  NEStewart  RBPowrozek  TARoy  KFMurphy  JMLi  TK Effect of neuropeptide Y (NPY) on oral ethanol intake in Wistar, alcohol-preferring (P), and -nonpreferring (NP) rats. Alcohol Clin Exp Res 2001;25 (3) 386- 390
PubMed Link to Article
Badia-Elder  NEStewart  RBPowrozek  TAMurphy  JMLi  TK Effects of neuropeptide Y on sucrose and ethanol intake and on anxiety-like behavior in high alcohol drinking (HAD) and low alcohol drinking (LAD) rats. Alcohol Clin Exp Res 2003;27 (6) 894- 899
PubMed Link to Article
Bennett  AJLesch  KPHeils  ALong  JCLorenz  JGShoaf  SEChampoux  MSuomi  SJLinnoila  MVHigley  JD Early experience and serotonin transporter gene variation interact to influence primate CNS function. Mol Psychiatry 2002;7 (1) 118- 122
PubMed Link to Article
Newman  TKSyagailo  YVBarr  CSWendland  JRChampoux  MGraessle  MSuomi  SJHigley  JDLesch  KP Monoamine oxidase A gene promoter variation and rearing experience influences aggressive behavior in rhesus monkeys. Biol Psychiatry 2005;57 (2) 167- 172
PubMed Link to Article
Barr  CSDvoskin  RLYuan  QLipsky  RHGupte  MHu  XZhou  ZSchwandt  MLLindell  SG McKee  MBecker  MLKling  MAGold  PWHigley  DHeilig  MSuomi  SJGoldman  D CRH haplotype as a factor influencing cerebrospinal fluid levels of corticotropin-releasing hormone, hypothalamic-pituitary-adrenal axis activity, temperament, and alcohol consumption in rhesus macaques. Arch Gen Psychiatry 2008;65 (8) 934- 944
PubMed Link to Article
Miller  GMBendor  JTiefenbacher  SYang  HNovak  MAMadras  BK A mu-opioid receptor single nucleotide polymorphism in rhesus monkey: association with stress response and aggression. Mol Psychiatry 2004;9 (1) 99- 108
PubMed Link to Article
Barr  CSSchwandt  MLNewman  TKHigley  JD The use of adolescent nonhuman primates to model human alcohol intake: neurobiological, genetic, and psychological variables. Ann N Y Acad Sci 2004;1021221- 233
PubMed Link to Article
Mayer  CMCai  FCui  HGillespie  JMMacMillan  MBelsham  DD Analysis of a repressor region in the human neuropeptide Y gene that binds Oct-1 and Pbx-1 in GT1-7 neurons. Biochem Biophys Res Commun 2003;307 (4) 847- 854
PubMed Link to Article
Higuchi  HNakano  KMiki  N Identification of NGF-response element in the rat neuropeptide Y gene and induction of the binding proteins. Biochem Biophys Res Commun 1992;189 (3) 1553- 1560
PubMed Link to Article
Kel-Margoulis  OVKel  AEReuter  IDeineko  IVWingender  E TRANSCompel: a database on composite regulatory elements in eukaryotic genes. Nucleic Acids Res 2002;30 (1) 332- 334
PubMed Link to Article
Heinemeyer  TWingender  EReuter  IHermjakob  HKel  AEKel  OVIgnatieva  EVAnanko  EAPodkolodnaya  OAKolpakov  FAPodkolodny  NLKolchanov  NA Databases on transcriptional regulation: TRANSFAC, TRRD and COMPEL. Nucleic Acids Res 1998;26 (1) 362- 367
PubMed Link to Article
Kasckow  JMulchahey  JJAguilera  GPisarska  MNikodemova  MChen  HCHerman  JPMurphy  EKLiu  YRizvi  TADautzenberg  FMSheriff  S Corticotropin-releasing hormone (CRH) expression and protein kinase A mediated CRH receptor signaling in an immortalized hypothalamic cell line. J Neuroendocrinol 2003;15 (5) 521- 529
PubMed Link to Article
Kim  HWhang  WWKim  HTPyun  KHCho  SYHahm  DHLee  HJShim  I Expression of neuropeptide Y and cholecystokinin in the rat brain by chronic mild stress. Brain Res 2003;983 (1-2) 201- 208
PubMed Link to Article
Higley  JDSuomi  SJLinnoila  M A nonhuman primate model of type II excessive alcohol consumption, 1: low cerebrospinal fluid 5-hydroxyindoleacetic acid concentrations and diminished social competence correlate with excessive alcohol consumption. Alcohol Clin Exp Res 1996;20 (4) 629- 642
PubMed Link to Article
Higley  JDSuomi  SJLinnoila  M CSF monoamine metabolite concentrations vary according to age, rearing, and sex, and are influenced by the stressor of social separation in rhesus monkeys. Psychopharmacology (Berl) 1991;103 (4) 551- 556
PubMed Link to Article
Barr  CSNewman  TKLindell  SShannon  CChampoux  MLesch  KPSuomi  SJGoldman  DHigley  JD Interaction between serotonin transporter gene variation and rearing condition in alcohol preference and consumption in female primates. Arch Gen Psychiatry 2004;61 (11) 1146- 1152
PubMed Link to Article
Schneider  MLMoore  CFSuomi  SJChampoux  M Laboratory assessment of temperament and environmental enrichment in rhesus monkey infants (Macaca mulatta). Am J Primatol 1991;25 (3) 137- 155
Link to Article
Champoux  MBennett  AShannon  CHigley  JDLesch  KPSuomi  SJ Serotonin transporter gene polymorphism, differential early rearing, and behavior in rhesus monkey neonates. Mol Psychiatry 2002;7 (10) 1058- 1063
PubMed Link to Article
Shannon  CSchwandt  MLChampoux  MShoaf  SESuomi  SJLinnoila  MHigley  JD Maternal absence and stability of individual differences in CSF 5-HIAA concentrations in rhesus monkey infants. Am J Psychiatry 2005;162 (9) 1658- 1664
PubMed Link to Article
Shoaf  SECarson  RHommer  DWilliams  WHigley  JDSchmall  BHerscovitch  PEckelman  WLinnoila  M Brain serotonin synthesis rates in rhesus monkeys determined by [11C]alpha-methyl-L-tryptophan and positron emission tomography compared to CSF 5-hydroxyindole-3-acetic acid concentrations. Neuropsychopharmacology 1998;19 (5) 345- 353
PubMed Link to Article
Ichise  MVines  DCGura  TAnderson  GMSuomi  SJHigley  JDInnis  RB Effects of early life stress on [11C]DASB positron emission tomography imaging of serotonin transporters in adolescent peer- and mother-reared rhesus monkeys. J Neurosci 2006;26 (17) 4638- 4643
PubMed Link to Article
Heinz  AHigley  JDGorey  JGSaunders  RCJones  DWHommer  DZajicek  KSuomi  SJLesch  KPWeinberger  DRLinnoila  M In vivo association between alcohol intoxication, aggression, and serotonin transporter availability in nonhuman primates. Am J Psychiatry 1998;155 (8) 1023- 1028
PubMed
Barr  CSSchwandt  MLindell  SGChen  SAGoldman  DSuomi  SJHigley  JDHeilig  M Association of a functional polymorphism in the mu-opioid receptor gene with alcohol response and consumption in male rhesus macaques. Arch Gen Psychiatry 2007;64 (3) 369- 376
PubMed Link to Article
Korotkova  TMBrown  RESergeeva  OAPonomarenko  AAHaas  HL Effects of arousal- and feeding-related neuropeptides on dopaminergic and GABAergic neurons in the ventral tegmental area of the rat. Eur J Neurosci 2006;23 (10) 2677- 2685
PubMed Link to Article
Fu  LYAcuna-Goycolea  Cvan den Pol  AN Neuropeptide Y inhibits hypocretin/orexin neurons by multiple presynaptic and postsynaptic mechanisms: tonic depression of the hypothalamic arousal system. J Neurosci 2004;24 (40) 8741- 8751
PubMed Link to Article
Karlsson  RMChoe  JSCameron  HAThorsell  ACrawley  JNHolmes  AHeilig  M The neuropeptide Y Y1 receptor subtype is necessary for the anxiolytic-like effects of neuropeptide Y, but not the antidepressant-like effects of fluoxetine in mice. Psychopharmacology (Berl) 2008;195 (4) 547- 557
PubMed Link to Article
Barr  CSNewman  TKSchwandt  MShannon  CDvoskin  RLLindell  SGTaubman  JThompson  BChampoux  MLesch  KPGoldman  DSuomi  SJHigley  JD Sexual dichotomy of an interaction between early adversity and the serotonin transporter gene promoter variant in rhesus macaques. Proc Natl Acad Sci U S A 2004;101 (33) 12358- 12363
PubMed Link to Article
Barr  CSSchwandt  MLLindell  SGHigley  JDMaestripieri  DGoldman  DSuomi  SJHeilig  M Variation at the mu-opioid receptor gene (OPRM1) influences attachment behavior in infant primates. Proc Natl Acad Sci U S A 2008;105 (13) 5277- 5281
PubMed Link to Article
Higuchi  HYang  HYSabol  SL Rat neuropeptide Y precursor gene expression. mRNA structure, tissue distribution, and regulation by glucocorticoids, cyclic AMP, and phorbol ester. J Biol Chem 1988;263 (13) 6288- 6295
PubMed
Wenger  TBouhdiba  MSaint Pol  PCiofi  PTramu  GLeonardelli  J Presence of neuropeptide–Y and its C-terminal flanking peptide immuno-reactivity in the seminiferous tubules of human testis. Andrologia 1990;22 (4) 299- 303
PubMed Link to Article
Morgan  CA  IIIWang  SSouthwick  SMRasmusson  AHazlett  GHauger  RLCharney  DS Plasma neuropeptide-Y concentrations in humans exposed to military survival training. Biol Psychiatry 2000;47 (10) 902- 909
PubMed Link to Article
Yehuda  RBrand  SYang  RK Plasma neuropeptide Y concentrations in combat exposed veterans: relationship to trauma exposure, recovery from PTSD, and coping. Biol Psychiatry 2006;59 (7) 660- 663
PubMed Link to Article
Heilig  MZachrisson  OThorsell  AEhnvall  AMottagui-Tabar  SSjogren  MAsberg  MEkman  RWahlestedt  CAgren  H Decreased cerebrospinal fluid neuropeptide Y (NPY) in patients with treatment refractory unipolar major depression: preliminary evidence for association with preproNPY gene polymorphism. J Psychiatr Res 2004;38 (2) 113- 121
PubMed Link to Article
Karvonen  MKPesonen  UKoulu  MNiskanen  LLaakso  MRissanen  ADekker  JMHart  LMValve  RUusitupa  MIJ Association of a leucine(7)-to-proline(7) polymorphism in the signal peptide of neuropeptide Y with high serum cholesterol and LDL cholesterol levels. Nat Med 1998;4 (12) 1434- 1437
PubMed Link to Article
Zhou  ZZhu  GHariri  AREnoch  MAScott  DSinha  RVirkkunen  MMash  DCLipsky  RHHu  XZHodgkinson  CAXu  KBuzas  BYuan  QShen  PHFerrell  REManuck  SBBrown  SMHauger  RLStohler  CSZubieta  JKGoldman  D Genetic variation in human NPY expression affects stress response and emotion. Nature 2008;452 (7190) 997- 1001
PubMed Link to Article
Ehlers  CLLi  TKLumeng  LHwang  BHSomes  CJimenez  PMathe  AA Neuropeptide Y levels in ethanol-naive alcohol-preferring and nonpreferring rats and in Wistar rats after ethanol exposure. Alcohol Clin Exp Res 1998;22 (8) 1778- 1782
PubMed Link to Article
Tecott  LHHeberlein  U Y do we drink? Cell 1998;95 (6) 733- 735
PubMed Link to Article
Thiele  TEMarsh  DJSte Marie  LBernstein  ILPalmiter  RD Ethanol consumption and resistance are inversely related to neuropeptide Y levels. Nature 1998;396 (6709) 366- 369
PubMed Link to Article
Carr  LGForoud  TBice  PGobbett  TIvashina  JEdenberg  HLumeng  LLi  TK A quantitative trait locus for alcohol consumption in selectively bred rat lines. Alcohol Clin Exp Res 1998;22 (4) 884- 887
PubMed Link to Article
Spence  JPLiang  THabegger  KCarr  LG Effect of polymorphism on expression of the neuropeptide Y gene in inbred alcohol-preferring and -nonpreferring rats. Neuroscience 2005;131 (4) 871- 876
PubMed Link to Article
Reich  TEdenberg  HJGoate  AWilliams  JTRice  JPVan Eerdewegh  PForoud  THesselbrock  VSchuckit  MABucholz  KKPorjesz  BLi  TKConneally  PMNurnberger  JIJ  JrTischfield  JACrowe  RRCloninger  CRWu  WShears  SCarr  KCrose  CWillig  CBegleiter  H Genome-wide search for genes affecting the risk for alcohol dependence. Am J Med Genet 1998;81 (3) 207- 215
PubMed Link to Article
Lappalainen  JKranzler  HRMalison  RPrice  LHVan Dyck  CRosenheck  RACramer  JSouthwick  SCharney  DKrystal  JGelernter  J A functional neuropeptide Y Leu7Pro polymorphism associated with alcohol dependence in a large population sample from the United States. Arch Gen Psychiatry 2002;59 (9) 825- 831
PubMed Link to Article
Mottagui-Tabar  SPrince  JAWahlestedt  CZhu  GGoldman  DHeilig  M A novel single nucleotide polymorphism of the neuropeptide Y (NPY) gene associated with alcohol dependence. Alcohol Clin Exp Res 2005;29 (5) 702- 707
PubMed Link to Article
Zhu  GPollak  LMottagui-Tabar  SWahlestedt  CTaubman  JVirkkunen  MGoldman  DHeilig  M NPY leu7pro and alcohol dependence in Finnish and Swedish populations. Alcohol Clin Exp Res 2003;27 (1) 19- 24
PubMed Link to Article
Zill  PPreuss  UWKoller  GBondy  BSoyka  M Analysis of single nucleotide polymorphisms and haplotypes in the neuropeptide Y gene: no evidence for association with alcoholism in a German population sample. Alcohol Clin Exp Res 2008;32 (3) 430- 434
PubMed Link to Article
Wetherill  LSchuckit  MAHesselbrock  VXuei  XLiang  TDick  DMKramer  JNurnberger  JI  JrTischfield  JAPorjesz  BEdenberg  HJForoud  T Neuropeptide Y receptor genes are associated with alcohol dependence, alcohol withdrawal phenotypes, and cocaine dependence. Alcohol Clin Exp Res 2008;32 (12) 2031- 2040
PubMed Link to Article
Valdez  GRKoob  GF Allostasis and dysregulation of corticotropin-releasing factor and neuropeptide Y systems: implications for the development of alcoholism. Pharmacol Biochem Behav 2004;79 (4) 671- 689
PubMed Link to Article

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