Selective, naloxone-reversible morphine depression of learned behavioral and hippocampal responses.
Morphine administered intravenously causes immediate and complete abolition of a simple learned response (classically conditioned nictitating membrane extension in rabbit) and of the associated learning-induced increase in hippocampal neuron activity. Both effects are completely reversed by low doses of naloxone. Morphine has no effect at all on behavioral performance of the unconditioned reflex response.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003213:Conditioning, Psychological / Q000187:drug effects*; D006624:Hippocampus / Q000502:physiology*; D008568:Memory / Q000187:drug effects; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D011817:Rabbits
D009270:Naloxone; D009020:Morphine