基于Morris 水迷宫探讨不同贮食行为鼠类的空间记忆

鼠类的贮食方式(分散或集中)与其空间记忆能力有关,但有关两者的定量关系尚缺少实验证据。朝鲜姬鼠(Apodemus peninsulae)分散或集中贮藏食物;社鼠(Niviventer confucianus)、黑线姬鼠(A. agrarius)、昆明小鼠(Mus musculus)仅集中贮藏食物。利用Morris 水迷宫对4 种鼠的空间记忆能力进行了评估,以探讨其空间记忆能力与食物贮藏方式间的联系。结果发现:在5 d 的定位航行实验中,4 种鼠找到隐藏平台的潜伏期均呈现出显著的下降趋势,其中朝鲜姬鼠潜伏期最短,黑线姬鼠与社鼠次之,昆明小鼠最长。在空间探索实验中,朝鲜姬鼠、黑线姬鼠和社鼠穿越平台的次数显著大于昆明小鼠;实验鼠在目标象限内的时间比和路程比为:朝鲜姬鼠> 黑线姬鼠> 社鼠>昆明小鼠,但差异不显著。结果表明具有分散贮藏行为的朝鲜姬鼠的空间记忆能力较仅具有集中贮藏行为的其它鼠种强,暗示鼠类的食物贮藏方式与其空间记忆能力有一定联系。

Studies on spatial memory of rodents with different food hoarding strategies using Morris water maze

The food strategies of rodents (e.g., scatter- or larder-hoarding) are related to their spatial memory; however, we lack quantitative experiments on these relationships. It is known that Apodemus peninsulae mainly scatter-hoard but also larder-hoard a few food items, but A. agrarius, Niviventer confucianus and Mus musculus only larder-hoard. In this study, the spatial memory of the four rodent species with different hoarding strategies was evaluated using a Morris water maze in order to illustrate the relationships between spatial memory and hoarding behavior. The results showed that the latency period of the four rodent species decreased significantly across the 5-day navigation experiment. The latent period was shortest in A. peninsulae but longest in M. musculus, followed by A. agrarius and N. confucianus. In the space exploration experiment, the frequency of crossing the platform in A. peninsulae, A. agrarius and N. confucianus was significantly higher than that of Mus musculus. The order of both time ratio and distance ratio in the target quadrant was: A. peninsulae > A. agrarius > N. niviventer > M. musculus, despite no significant difference. The results indicate that the spatial memory of A. peninsulae with scatter-hoarding behavior may be stronger than that of the other rodent species with larder-hoarding behavior, suggesting that the food storage strategy of rodent species is closely related to spatial memory.