Bak Jia, Pyeon Hae-In, Seok Jin-I, Choi Yun-Sik
Department of Pharmaceutical Science and Technology, College of Biomedical Science, Catholic University of Daegu, 38430 GyeongSangBukDo, Republic of Korea.
Department of Pharmaceutical Science and Technology, College of Biomedical Science, Catholic University of Daegu, 38430 GyeongSangBukDo, Republic of Korea.
Behav Brain Res. 2017 Mar 1;320:219-224. doi: 10.1016/j.bbr.2016.12.011. Epub 2016 Dec 12.
Y maze has been used to test spatial working memory in rodents. To this end, the percentage of spontaneous alternation has been employed. Alternation indicates sequential entries into all three arms; e.g., when an animal visits all three arms clockwise or counterclockwise sequentially, alternation is achieved. Interestingly, animals have a tendency to rotate or turn to a preferred side. Thus, when an animal has a high rotation preference, this may influence their alternation behavior. Here, we have generated a new analytical method, termed entropy of spontaneous alternation, to offset the effect of rotation preference on Y maze. To validate the entropy of spontaneous alternation, we employed a free rotation test using a cylinder and a spatial working memory test on Y maze. We identified that mice showed 65.1% rotation preference on average. Importantly, the percentage of spontaneous alternation in the high preference group (more than 70% rotation to a preferred side) was significantly higher than that in the no preference group (<55%). In addition, there was a clear correlation between rotation preference on cylinder and turning preference on Y maze. On the other hand, this potential leverage effect that arose from rotation preference disappeared when the animal behavior on Y maze was analyzed with the entropy of spontaneous alternation. Further, entropy of spontaneous alternation significantly determined the loss of spatial working memory by scopolamine administration. Combined, these data indicate that the entropy of spontaneous alternation provides higher credibility when spatial working memory is evaluated using Y maze.
Y迷宫已被用于测试啮齿动物的空间工作记忆。为此，采用了自发交替的百分比。交替表示依次进入所有三个臂；例如，当动物按顺时针或逆时针顺序依次访问所有三个臂时，就实现了交替。有趣的是，动物有向偏好侧旋转或转弯的倾向。因此，当动物有较高的旋转偏好时，这可能会影响它们的交替行为。在这里，我们开发了一种新的分析方法，称为自发交替熵，以抵消旋转偏好在Y迷宫中的影响。为了验证自发交替熵，我们使用圆柱体进行了自由旋转测试，并在Y迷宫上进行了空间工作记忆测试。我们发现小鼠平均表现出65.1%的旋转偏好。重要的是，高偏好组（向偏好侧旋转超过70%）的自发交替百分比显著高于无偏好组（<55%）。此外，圆柱体上的旋转偏好与Y迷宫上的转弯偏好之间存在明显的相关性。另一方面，当用自发交替熵分析动物在Y迷宫上的行为时，由旋转偏好产生的这种潜在杠杆效应消失了。此外，自发交替熵显著决定了东莨菪碱给药导致的空间工作记忆丧失。综合这些数据表明，当使用Y迷宫评估空间工作记忆时，自发交替熵具有更高的可信度。
