Effects of bremazocine on passive avoidance behaviour in mice.
The effects of bremazocine on memory processes were studied in DBA/2 mice tested in a passive avoidance apparatus. In a first set of experiments, memory impairments following immediately posttraining bremazocine administration (0.025 and 0.05 but not 0.01 mg/kg), and memory improvements following immediately posttraining administration of the kappa-opioid-receptor antagonist MR-1452 (1.0 and 2.0 but not 0.5 mg/kg), were observed. No effect was evident when the drugs were injected starting 120 min after training. In a second set of experiments, the effects of bremazocine (0.05 mg/kg) were antagonized by a per se ineffective dose of MR-1452 (0.5 mg/kg), suggesting involvement of kappa-opioid-receptors. In a third set of experiments, the effects of bremazocine were enhanced by a per se ineffective (15 min) immobilization stress, and were decreased by familiarization with the passive avoidance apparatus. The results are discussed in terms of attenuation of emotionality following bremazocine administration.
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001575:Benzomorphans / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009019:Morphinans / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology; D012149:Restraint, Physical; D013315:Stress, Psychological
D000700:Analgesics; D001575:Benzomorphans; D009019:Morphinans; D009292:Narcotic Antagonists; C029552:Mr 1452; C027248:bremazocine