Division of Integrative Bioscience, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Sciences, Yonago, Japan.
Division of Neurobiology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Japan.
Neurosci Res. 2017 Oct;123:27-35. doi: 10.1016/j.neures.2017.04.012. Epub 2017 Apr 24.
The open field test is one of the most popular ethological tests to assess anxiety-like behavior in rodents. In the present study, we examined the effect of early deprivation (ED), a model of early life stress, on anxiety-like behavior in rats. In ED animals, we failed to find significant changes in the time spent in the center or thigmotaxis area of the open field, the common indexes of anxiety-like behavior. However, we found a significant increase in high-leaning behavior in which animals lean against the wall standing on their hindlimbs while touching the wall with their forepaws at a high position. The high-leaning behavior was decreased by treatment with an anxiolytic, diazepam, and it was increased under intense illumination as observed in the center activity. In addition, we compared the high-leaning behavior and center activity under various illumination intensities and found that the high-leaning behavior is more sensitive to illumination intensity than the center activity in the particular illumination range. These results suggest that the high-leaning behavior is a novel anxiety-like behavior in the open field test that can complement the center activity to assess the anxiety state of rats.
旷场实验是评估啮齿类动物焦虑样行为的最常用行为学测试之一。在本研究中，我们研究了早期剥夺（ED），即一种早期生活应激模型，对大鼠焦虑样行为的影响。在 ED 动物中，我们未能发现旷场中心或触壁区域停留时间的显著变化，这是焦虑样行为的常见指标。然而，我们发现一种显著的高倾斜行为增加，即动物后腿站立，前爪触及高位置的墙壁，从而倾斜靠墙。抗焦虑药物地西泮可降低高倾斜行为，而在强烈光照下，如在中心活动中观察到的那样，高倾斜行为增加。此外，我们比较了不同光照强度下的高倾斜行为和中心活动，发现高倾斜行为在特定光照范围内比中心活动对光照强度更敏感。这些结果表明，高倾斜行为是旷场测试中一种新颖的焦虑样行为，可以补充中心活动来评估大鼠的焦虑状态。
