Yamamoto Yasuko, Adachi Yutaka, Fujii Yoko, Kamei Chiaki
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan.
Nihon Shinkei Seishin Yakurigaku Zasshi. 2005 Apr;25(2):85-90.
Ginkgo biloba extract is widely used as a herbal medicine or dietary supplement in Europe, since Ginkgo biloba extract is effective in facilitation of learning and recollection of memories. However, little is known about the mechanism of the action of Ginkgo biloba extract on learning and memory enhancements. On the other hand, it is well known that cholinergic, histaminergic and glutamatergic systems play a crucial role in learning and memory in animals. Therefore, in order to elucidate the mechanism of Ginkgo biloba extract on memory, we studied and clarified the effect of Ginkgo biloba extract on spatial memory deficits induced by scopolamine, diphenhydramine or MK-801 using eight-arm radial maze performance. It was found that Ginkgo biloba extract improved the spatial memory deficits induced by scopolamine. Ginkgo biloba extract also caused repair to spatial memory deficits induced by diphenhydramine. On the other hand, no significant effect was observed with MK-801-induced spatial memory deficits. These findings suggest that the effect of Ginkgo biloba extract is mediated not only by the cholinergic system but also by the histaminergic system to induce learning and memory enhancements.
银杏叶提取物在欧洲被广泛用作草药或膳食补充剂，因为银杏叶提取物在促进学习和记忆方面是有效的。然而，关于银杏叶提取物增强学习和记忆作用的机制却知之甚少。另一方面，众所周知，胆碱能、组胺能和谷氨酸能系统在动物的学习和记忆中起着至关重要的作用。因此，为了阐明银杏叶提取物对记忆的作用机制，我们利用八臂放射状迷宫实验研究并明确了银杏叶提取物对东莨菪碱、苯海拉明或MK-801诱导的空间记忆缺陷的影响。结果发现，银杏叶提取物改善了东莨菪碱诱导的空间记忆缺陷。银杏叶提取物也修复了苯海拉明诱导的空间记忆缺陷。另一方面，对于MK-801诱导的空间记忆缺陷未观察到显著效果。这些发现表明，银杏叶提取物的作用不仅通过胆碱能系统介导，还通过组胺能系统介导，从而诱导学习和记忆增强。
