Packard M G
Department of Psychology, University of New Orleans, New Orleans, Louisiana, 70148, USA.
Horm Behav. 1998 Oct;34(2):126-39. doi: 10.1006/hbeh.1998.1464.
The present paper provides a review of recent research carried out in this laboratory investigating the effects of posttraining peripheral and intrahippocampal injection of estradiol on memory in rats, and estradiol-acetylcholine interactions in memory modulation. Ovariectomized rats received an eight-trial training session in a hippocampal-dependent hidden platform water maze task. Immediately following training, rats received a posttraining peripheral or intrahippocampal injection of estradiol-cyclodextrin complex or vehicle. Twenty-four hours later rats were returned to the maze for a retention test session, and latency to escape was used as a measure of memory for the previous day's training. Peripheral posttraining injection of estradiol enhances memory relative to vehicle-treated rats. Injections of estradiol given 2 h posttraining has no effect on retention, indicating a time-dependent effect of estradiol on memory storage processes. A time-dependent memory enhancing effect of posttraining intrahippocampal injections of estradiol has also been observed in both male and ovariectomized female rats. The memory enhancing effect of peripheral posttraining injection of estradiol in ovariectomized rats is blocked by a subeffective dose of the acetylcholine muscarinic receptor antagonist scopolamine, suggesting that estradiol interacts with cholinergic systems in memory modulation. Concurrent peripheral posttraining injection of a subeffective dose of estradiol and a subeffective dose of the cholinergic agonist oxotremorine produces a synergistic memory enhancing effect. The findings suggest that: (1) estradiol selectively influences memory storage independent of an effect on nonmnemonic processes, (2) the hippocampus is a potential neuroanatomical site of action mediating estrogenic effects on memory, and (3) estradiol interacts with cholinergic systems in memory modulation.
本文综述了本实验室最近开展的研究，该研究调查了训练后外周和海马内注射雌二醇对大鼠记忆的影响，以及雌二醇与乙酰胆碱在记忆调节中的相互作用。去卵巢大鼠在海马依赖性隐藏平台水迷宫任务中接受了八次训练。训练结束后，大鼠立即接受训练后外周或海马内注射雌二醇 - 环糊精复合物或溶剂。24小时后，将大鼠放回迷宫进行记忆保持测试，逃避潜伏期用作前一天训练记忆的指标。与接受溶剂处理的大鼠相比，训练后外周注射雌二醇可增强记忆。训练后2小时注射雌二醇对记忆保持没有影响，表明雌二醇对记忆存储过程具有时间依赖性效应。在雄性和去卵巢雌性大鼠中也观察到训练后海马内注射雌二醇具有时间依赖性的记忆增强作用。训练后外周注射雌二醇对去卵巢大鼠的记忆增强作用被乙酰胆碱毒蕈碱受体拮抗剂东莨菪碱的亚有效剂量所阻断，这表明雌二醇在记忆调节中与胆碱能系统相互作用。训练后同时外周注射亚有效剂量的雌二醇和亚有效剂量的胆碱能激动剂氧化震颤素可产生协同的记忆增强作用。这些发现表明：（1）雌二醇选择性地影响记忆存储，而不影响非记忆过程；（2）海马是介导雌激素对记忆作用的潜在神经解剖作用部位；（3）雌二醇在记忆调节中与胆碱能系统相互作用。
