Levin E D, Kaplan S, Boardman A
Department of Psychiatry, Duke University Medical Center, Durham, NC 27710, USA.
Behav Pharmacol. 1997 Jun;8(2-3):236-42.
In the 8-arm radial maze and other tests, acute nicotine administration has been found to improve memory performance significantly, whereas acute administration of the nicotinic antagonist mecamylamine has been found to impair memory performance. However, questions remain concerning the behavioral and pharmacological nature of acute nicotine effects on memory. In the current studies, we examined acute nicotine effects on working and reference memory in a 16-arm radial maze. In the first study, nicotine caused a significant improvement in working memory but not in reference memory. The muscarinic antagonist scopolamine caused significant deficits in working memory but not in reference memory. Nicotine did not significantly attenuate the scopolamine-induced deficit. In the second study, with rats trained to near-perfect performance, a low dose of mecamylamine (1.25 mg/kg) caused a significant working memory impairment in the 16-arm maze. This deficit was significantly attenuated by concurrent acute administration of nicotine. These studies show that acute nicotine, like chronic nicotine, preferentially improves working compared with reference memory in the radial-arm maze. Mecamylamine can impair working memory performance in the 16-arm maze at low doses which are less likely to have effects at N-methyl-D-aspartate receptors. Nicotine can selectively reverse mecamylamine-induced deficits.
在八臂放射状迷宫及其他测试中，已发现急性给予尼古丁可显著改善记忆表现，而急性给予烟碱拮抗剂美加明则会损害记忆表现。然而，关于急性尼古丁对记忆影响的行为学和药理学本质仍存在疑问。在当前研究中，我们在十六臂放射状迷宫中检测了急性尼古丁对工作记忆和参考记忆的影响。在第一项研究中，尼古丁使工作记忆有显著改善，但对参考记忆无此作用。毒蕈碱拮抗剂东莨菪碱使工作记忆出现显著缺陷，但对参考记忆无影响。尼古丁并未显著减轻东莨菪碱所致的缺陷。在第二项研究中，对训练至近乎完美表现的大鼠，低剂量美加明（1.25毫克/千克）在十六臂迷宫中导致显著的工作记忆损害。同时急性给予尼古丁可显著减轻这一缺陷。这些研究表明，与慢性尼古丁一样，急性尼古丁在放射状迷宫中优先改善工作记忆而非参考记忆。低剂量美加明可损害十六臂迷宫中的工作记忆表现，而此剂量对N-甲基-D-天冬氨酸受体产生作用的可能性较小。尼古丁可选择性逆转美加明所致的缺陷。
