title: Retrograde memory enhancement by diazepam: its relation to anterograde amnesia, and some clinical implications.
abstract: The effect of diazepam on retention of an inhibitory avoidance task was investigated in mice. In Experiment 1, animals were trained in this task, and tested for retention 24 h later. The mice received, 20 min after training, an IP injection of either diazepam (2 mg/kg) or saline; half of the mice in each treatment group were exposed, 40 min after avoidance training (and 20 min after the injections) to a Y maze. Exposure to the Y maze disrupted retention of the avoidance task in the saline-treated animals, and enhanced it in the diazepam-treated mice. Retention of habituation to the Y maze was impaired in the diazepam group. The effect can be explained by an interaction of the drug with the Y maze, by which exposure to the Y maze became facilitatory, instead of deleterious, to retention of the avoidance task. This may or may not be related to anterograde amnesia for the Y maze; and may be related to effects of diazepam seen in clinical practice. In Experiment 2, diazepam was given prior to, instead of after, inhibitory avoidance training; it caused anterograde amnesia for this task, which was not reversed by pre-test diazepam, and was therefore not due to state dependency. In conclusion, the effect of diazepam on inhibitory avoidance learning depends on the time at which the drug is given. A pretraining injection causes amnesia, whereas a post-training injection, while ineffective per se, may facilitate retention of the task when it is followed by exposure to a habituation procedure.
mesh_terms: D000647:Amnesia / Q000139:chemically induced*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D003975:Diazepam / Q000494:pharmacology*; D004334:Drug Administration Schedule; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D012153:Retention, Psychology / Q000187:drug effects*; D013997:Time Factors
chemical_list: D003975:Diazepam