Facilitation of memory retrieval by pre-test morphine and its state dependency in the step-through type passive avoidance learning test in mice.
Amnesia produced by scopolamine and cycloheximide were reversed by morphine given 30 min before the test trial (pre-test), and pre-test morphine also facilitated the memory retrieval in the animals administered naloxone during the training trial. Similarly, pre-test scopolamine partially reversed the scopolamine-induced amnesia, but not significantly; and pre-test cycloheximide failed to reverse the cycloheximide-induced amnesia. These results suggest that the facilitation of memory retrieval by pre-test morphine might be the direct action of morphine rather than a state dependent effect.
Shiigi
Y
Y
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Nagasaki University, Japan.
Kaneto
H
H
D000647:Amnesia / Q000139:chemically induced*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D003513:Cycloheximide / Q000008:administration & dosage / Q000037:antagonists & inhibitors*; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone; D011292:Premedication; D012601:Scopolamine / Q000008:administration & dosage / Q000037:antagonists & inhibitors*; D013997:Time Factors
D009270:Naloxone; D009020:Morphine; D003513:Cycloheximide; D012601:Scopolamine