Joyal C C, Meyer C, Jacquart G, Mahler P, Caston J, Lalonde R
Université de Montréal, Département de Psychologie, Qué, Canada.
Brain Res. 1996 Nov 11;739(1-2):1-11. doi: 10.1016/s0006-8993(96)00333-2.
Rats were lesioned in the midline cerebellum, comprising the vermis and fastigial nucleus, or the lateral cerebellum, comprising the cerebellar hemispheres and dentate nucleus, and evaluated in a series of motor and non-motor learning tests. Rats with midline lesions had difficulty in maintaining their equilibrium on a bridge and were slower before turning upward and traversed less squares on an inclined grid. They were not impaired for muscle strength when suspended from a horizontal wire. Rats with lateral lesions had milder deficits on the bridge and were not affected in the other two tests. In the Morris water maze test, rats with lateral lesions were deficient in spatial orientation, whereas rats with midline lesions were deficient in visuomotor coordination. Lateral lesions had no effects on visual discrimination learning. These results illustrate the differential influence of midline as opposed to lateral cerebellar regions on both motor and non-motor behaviors. Fastigial nucleus lesions decreased the time spent in equilibrium and latencies before falling on the bridge and the distance travelled along the inclined grid but had no effect on muscle strength when suspended from the horizontal string. Quadrant entries and escape latencies were higher in rats with fastigial lesions during the hidden platform condition of the Morris water maze but not during the visible platform condition. It is concluded that fastigial-lesioned rats are impaired in equilibrium and spatial orientation but with repeated trials learn to improve their performances.
大鼠的小脑中线（包括蚓部和顶核）或小脑外侧（包括小脑半球和齿状核）受到损伤，并在一系列运动和非运动学习测试中进行评估。中线损伤的大鼠在桥上保持平衡有困难，向上转身前速度较慢，在倾斜网格上走过的方格较少。当它们从水平金属丝上悬吊时，肌肉力量没有受损。外侧损伤的大鼠在桥上的缺陷较轻，在其他两项测试中未受影响。在莫里斯水迷宫测试中，外侧损伤的大鼠在空间定向方面存在缺陷，而中线损伤的大鼠在视觉运动协调方面存在缺陷。外侧损伤对视觉辨别学习没有影响。这些结果说明了小脑中线区域与外侧区域对运动和非运动行为的不同影响。顶核损伤减少了在桥上保持平衡的时间和掉落前的潜伏期，以及在倾斜网格上行走的距离，但当从水平绳子上悬吊时对肌肉力量没有影响。在莫里斯水迷宫的隐藏平台条件下，顶核损伤的大鼠进入象限的次数和逃避潜伏期较高，但在可见平台条件下则不然。得出的结论是，顶核损伤的大鼠在平衡和空间定向方面受损，但通过反复试验可以学会提高其表现。
