Ethanol-induced state-dependent learning is mediated by 5-hydroxytryptamine3 receptors but not by N-methyl-D-aspartate receptor complex.
Involvement of N-methyl-D-aspartate (NMDA) receptor complex and 5-hydroxytryptamine3 (5-HT3) receptors in state-dependent learning (SDL) induced by ethanol (EtOH) was investigated in the step-through passive avoidance task in rats. Pre-training injections of EtOH or MK-801 reduced step-through latency in the test session conducted 24 h after the training session. Pre-test as well as pre-training injections of EtOH failed to reduce the latency, while pre-training and pre-test injections of MK-801 reduced the latency. These results show that EtOH but not MK-801 produces SDL. SDL induced by EtOH was blocked by ICS205-930 injected before either the training or test session. However, ICS205-930 failed to block SDL induced by diazepam and muscimol. These results suggest that NMDA receptor complex may not be involved in SDL, and that 5-HT3 receptors may contribute to SDL induced by EtOH but not by diazepam and muscimol.
Nakagawa
Y
Y
Tsukuba Research Laboratories, Experimental Biomedical Research Inc. (Jisseiken), Ibaraki, Japan.
Iwasaki
T
T
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D003975:Diazepam / Q000494:pharmacology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D009118:Muscimol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D011985:Receptors, Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D000077526:Tropisetron
D018691:Excitatory Amino Acid Antagonists; D007211:Indoles; D016194:Receptors, N-Methyl-D-Aspartate; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D009118:Muscimol; D000431:Ethanol; D000077526:Tropisetron; D016291:Dizocilpine Maleate; D003975:Diazepam