Aitken Phillip, Zheng Yiwen, Smith Paul F
Department of Pharmacology and Toxicology, School of Biomedical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
Brain Research New Zealand Centre of Research Excellence for Hearing and Balance Research, University of Auckland, New Zealand.
J Vestib Res. 2017;27(2-3):89-101. doi: 10.3233/VES-170612.
Bilateral vestibular loss (BVL) causes a unique behavioural syndrome in rodents, with symptoms such as locomotor hyperactivity and changes in exploratory behaviour. Many of these symptoms appear to be indirect consequences of the loss of vestibular reflex function and are difficult to explain. Although such symptoms have been reported before, there have been few systematic studies of the effects of BVL using automated digital tracking systems in which many behavioural symptoms can be measured simultaneously with high precision. In this study, data were obtained from rats with BVL induced by intratympanic sodium arsanilate injections (n = 7) or sham injections (n = 8) and their behaviour in the open field was measured at 3 days and 23 days post-injection using Ethovision™ tracking software. BVL rats demonstrated reduced thigmotaxis, with more time spent in the central zones. Twenty-three days post-injection, BVL animals showed increased locomotor activity in the open field. The increase in activity was also reflected in the number of transitions between each zone of the field. In addition to increased activity, BVL animals showed increased whole body rotations following lesions. Using linear discriminant analysis (LDA) and random forest classification (RFC), we were able to show that the indirect behavioural effects of BVL, excluding direct measurement of vestibular reflex function, could correctly predict whether animals had received a BVL with a high degree of accuracy at both day 3 and day 23 post-BVL (83% and 100% for LDA, and 100% and 100% for RFC, respectively). RFC has been similarly successful in classifying other hyperactivity syndromes such as attention deficit hyperactivity disorder. These results suggest that BVL results in a unique behavioural signature that can identify vestibular loss in rats even without direct vestibular reflex measurements.
双侧前庭丧失（BVL）在啮齿动物中会引发一种独特的行为综合征，伴有运动亢进和探索行为改变等症状。这些症状中的许多似乎是前庭反射功能丧失的间接后果，难以解释。尽管此前已有此类症状的报道，但使用自动化数字跟踪系统对BVL的影响进行的系统研究较少，在该系统中可以高精度地同时测量多种行为症状。在本研究中，从经鼓室内注射对氨基苯胂酸钠诱导BVL的大鼠（n = 7）或假注射大鼠（n = 8）获取数据，并在注射后第3天和第23天使用Ethovision™跟踪软件测量它们在旷场中的行为。BVL大鼠表现出趋触性降低，在中央区域花费的时间更多。注射后23天，BVL动物在旷场中的运动活动增加。活动的增加也反映在旷场各区域之间的转换次数上。除了活动增加外，BVL动物在损伤后全身旋转也增加。使用线性判别分析（LDA）和随机森林分类（RFC），我们能够表明，BVL的间接行为效应（不包括前庭反射功能的直接测量）在BVL后第3天和第23天都能以高度准确性正确预测动物是否患有BVL（LDA分别为83%和100%，RFC分别为100%和100%）。RFC在对其他多动综合征如注意力缺陷多动障碍进行分类方面也同样成功。这些结果表明，BVL会导致一种独特的行为特征，即使不直接测量前庭反射，也能识别大鼠中的前庭丧失。
