大鼠黑质毁损程度的行为学评价

A BEHAVIORAL EVALUATION OF SUBSTANTIA NIGRA PARS COMPACTA LESIONED RATS

本研究通过观察黑质毁损大鼠的行为学变化及其与毁损程度的相关性,评价开野实验作为毁损程度观察指标的可行性。采用6-羟基多巴胺(6-OHDA)单侧一点注射毁损大鼠黑质致密区(SNC)多巴胺(DA)能神经元,采用开野实验和阿朴吗啡(APO)诱导旋转实验,观察术后1、3、5、7、14、21 d行为学变化;利用Nissl染色和免疫组织化学方法观察各时间点黑质形态学变化。结果显示:毁损侧黑质DA能神经元逐渐减少;开野实验中旋转、探究、后肢站立和穿梭行为在术后1 d即有显著改变(与对照组比较P<0.05),其中,旋转行为与毁损程度呈正相关(r=0.471,P<0.01),探究、后肢站立和穿梭行为与毁损程度呈负相关(r分别为-0.719、-0.589、-0.594,P<0.01);术后14 d毁损比例超过80%,APO诱导旋转实验阳性。因此开野实验可作为毁损早期反映大鼠脑内DA耗竭程度的敏感的行为学观察指标。

To evaluate the acceptability of the open-field test as a predictor of lesion size, rats received a unilateral injection of 6-hydroxydopamine (6-OHDA) into the substantia nigra pars compacta (SNc). Behavioral changes in the open-field and rotations induced by apomorphine (APO) were investigated 1d, 3d, 5d, 7d, 14 d, 21 d after lesion. Meanwhile dopaminergic degeneration were observed with Nissl staining and immunocytochemistry. Dopaminergic neurons decreased gradually in the le-sioned site. All parameters of open-field except grooming had a notable alternation 1 d after lesion (P<0. 05). The correlation analyses yielded a positive relationship between turning and lesion size(r = 0. 471,P<0. 01), while scanning, rearing and loco-motor activity were negtively correlated with lesion size(r= - 0. 719, r= - 0. 589, r= -0. 594, respectively; P<0. 01). Furthermore the rotation behavior induced by APO was positive when the lesion was severe(>80%). These results indicate that the open-field test is useful to predict lesion size.