Opioid antagonist eliminates the stress-induced impairment of long-term potentiation (LTP).
Rats (n = 20) were injected with the opioid antagonist naltrexone and half were exposed to inescapable shock/restraint. Another 20 rats were injected with saline and half were exposed to shock. Neither saline nor naltrexone alone had any effect on hippocampal LTP. A large reduction in LTP was observed in saline rats exposed to shock, while normal LTP developed in the naltrexone rats exposed to shock. Thus, naltrexone eliminated the impairment, and thereby implicated endogenous opioids in the mechanism responsible for the stress-induced impairment of LTP.
Shors
T J
TJ
University of Southern California, Department of Psychology, Los Angeles 90089.
Levine
S
S
Thompson
R F
RF
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D009271:Naltrexone / Q000494:pharmacology*; D009473:Neuronal Plasticity; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology*
D011957:Receptors, Opioid; D009271:Naltrexone