title: Ethanol improves short-term social memory in rats. Involvement of opioid and muscarinic receptors.
abstract: Some human and animal studies have demonstrated enhancement of memory processes when ethanol was administered immediately after training and subjects were later tested in the drug-free state. The aim of this study was to evaluate the effect of acute ethanol administration (0.5, 1.0 and 2.0 g/kg) by intraperitoneal (i.p.) and oral route on short-term memory, using the social recognition test in rats. The actions of scopolamine (0.06 and 0.5 mg/kg, i.p.) and naloxone (1.0 mg/kg, i.p.) and their interaction with ethanol in relation to short-term memory were also studied. The doses of ethanol used did not show any sedative effect, which was assessed by measuring locomotor activity. The results indicate that acute low doses of ethanol (0.5 and 1.0 g/kg, i.p.) improve the short-term olfactory memory in rats in a specific and time-dependent manner, and that this action is, at least in part, related to opioid, but not to muscarinic receptors. In addition, these findings confirm that the social recognition test in rats is a useful and reliable model to investigate short-term memory affected by ethanol.
authors.affiliation: Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, UFSC, Rua Ferreira Lima 82, 88015-420 Florianópolis SC, Brazil.
authors.forename: Rui D S
authors.initials: RD
authors.lastname: Prediger
authors.forename: Reinaldo N
authors.initials: RN
authors.lastname: Takahashi
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects*; D009043:Motor Activity / Q000187:drug effects; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology*; D011957:Receptors, Opioid / Q000502:physiology; D012601:Scopolamine / Q000494:pharmacology; D012919:Social Behavior; D013997:Time Factors
chemical_list: D002492:Central Nervous System Depressants; D018727:Muscarinic Antagonists; D009292:Narcotic Antagonists; D011976:Receptors, Muscarinic; D011957:Receptors, Opioid; D009270:Naloxone; D000431:Ethanol; D012601:Scopolamine