RT Journal
A1 Talamini LM, Meeter M, Elvevåg B, Murre JJ, Goldberg TE
T1 REduced parahippocampal connectivity produces schizophrenia-like memory deficits in simulated neural circuits with reduced parahippocampal connectivity
JF Archives of General Psychiatry
JO Archives of General Psychiatry
YR 2005
FD May 1
VO 62
IS 5
SP 485
OP 493
DO 10.1001/archpsyc.62.5.485
UL http://dx.doi.org/10.1001/archpsyc.62.5.485
AB Context 
    Episodic memory impairments are well characterized in schizophrenia, but their neural origin is unclear.Objective 
    To determine whether the episodic memory impairments in schizophrenia may originate from reduced parahippocampal connectivity.Design 
    Experimental in silico model.Setting 
    Department of Psychology, University of Amsterdam, Amsterdam, the Netherlands.Interventions 
    A new, in silico medial temporal lobe model that simulates normal performance on a variety of episodic memory tasks was devised. The effects of reducing parahippocampal connectivity in the model (from perirhinal and parahippocampal cortex to entorhinal cortex and from entorhinal cortex to hippocampus) were evaluated and compared with findings in schizophrenic patients. Alternative in silico neuropathologies, increased noise and loss of hippocampal neurons, were also evaluated.Results 
    In the model, parahippocampal processing subserves integration of different cortical inputs to the hippocampus and feature extraction during recall. Reduced connectivity in this area resulted in a pattern of deficits that closely mimicked the impairments in schizophrenia, including a mild recognition impairment and a more severe impairment in free recall. Furthermore, the schizophrenic model was not differentially sensitive to interference, also consistent with behavioral data. Notably, neither increased noise levels nor a reduction of hippocampal nodes in the model reproduced this characteristic memory profile.Conclusions 
    Taken together, these findings highlight the importance of parahippocampal neuropathology in schizophrenia, demonstrating that reduced connectivity in this region may underlie episodic memory problems associated with the disorder.