Sedative-like Effect of Epinephrine:  A Review

WHEN HEN FELDBERG and Sherwood demonstrated that intraventricular injections of epinephrine (Adrenaline) in dogs caused "sedative-like" behavioral depression, they suggested that epinephrine secretion during anxiety in humans might cause analogous symptoms of fatigue and somnolence.¹⁸ Little or no attention was subsequently given this hypothesis; Feldberg himself did not mention it in his recent (1963) book about the pharmacology of the brain.¹⁷ The hypothesis has received little attention for two reasons: first, there has been little evidence that systemic epinephrine could reach the brain, and second, there has been little or no evidence that systemically administered epinephrine could produce sedative-like or fatiguelike effects.

Both these objections have been modified by recent experimental findings. First, radioactively tagged epinephrine has been shown to cross the blood-brain barrier in the region of the hypothalamus during sustained systemic infusions,^1,45 and second, epinephrine