Blaker W D, Cheney D L, Gandolfi O, Costa E
J Pharmacol Exp Ther. 1983 May;225(2):361-5.
The relationship between regulation of acetylcholine metabolism in the septal-hippocampal pathway and extinction of a food reinforced lever press response was investigated by comparing the turnover rate of acetylcholine (TRACh) in the rat hippocampus with the amount of responding during extinction after intraseptal injection of the gamma-aminobutyric acid receptor agonist muscimol. Doses (0.3-3.0 nmol) which decreased the TRACh in the hippocampus also increased the responding during extinction over that of saline controls. Responding during the continuous reinforcement schedule before extinction was also increased, but to a lesser extent. Higher doses (10-30 nmol) further decreased the TRACh in the hippocampus, decreased it in the cortex and were accompanied by irregular responding and sedation. The TRACh in the hippocampus was also measured in drug-free rats undergoing extinction after training on a continuous reinforcement or variable interval 60 sec reinforcement schedule. Although the variable interval 60 sec reinforcement schedule rats responded more than the continuous reinforcement rats during extinction, there were no differences between the TRACh in the hippocampus. The present results indicate that the decrease in the hippocampal TRACh which is produced by intraseptal muscimol is accompanied by an increase in the response rate during extinction, but that operantly induced differences in this behavior are not accompanied by detectable changes in hippocampal TRACh.
通过比较大鼠海马中乙酰胆碱周转率（TRACh）与在隔区内注射γ-氨基丁酸受体激动剂蝇蕈醇后消退期的反应量，研究了隔区-海马通路中乙酰胆碱代谢调节与食物强化杠杆按压反应消退之间的关系。降低海马中TRACh的剂量（0.3 - 3.0纳摩尔）也使消退期的反应比生理盐水对照组增加。在消退前的连续强化阶段的反应也增加了，但程度较小。更高剂量（10 - 30纳摩尔）进一步降低了海马中的TRACh，降低了皮质中的TRACh，并伴有不规则反应和镇静作用。还对在连续强化或60秒可变间隔强化程序训练后进行消退的无药物大鼠测量了海马中的TRACh。尽管在消退期60秒可变间隔强化程序组的大鼠比连续强化组的大鼠反应更多，但海马中的TRACh没有差异。目前的结果表明，隔区内注射蝇蕈醇导致的海马TRACh降低与消退期反应率增加有关，但这种行为中操作性诱导的差异并没有伴随着海马TRACh的可检测变化。
