LOCOMOTION OF AGED RATS - RELATIONSHIP TO NEUROCHEMICAL BUT NOT MORPHOLOGICAL-CHANGES IN NIGROSTRIATAL DOPAMINERGIC-NEURONS
LOCOMOTION OF AGED RATS - RELATIONSHIP TO NEUROCHEMICAL BUT NOT MORPHOLOGICAL-CHANGES IN NIGROSTRIATAL DOPAMINERGIC-NEURONS
复制标题
DOI：
10.1016/0361-9230(93)90294-l
复制
发表时间：
1993-01-01
影响因子：
3.8
通讯作者：
SANBERG, PR
中科院分区：
文献类型：
--
作者：
EMERICH, DF;MCDERMOTT, P;SANBERG, PR
在年轻（5-6月龄）和老年（24-25月龄）大鼠中评价自发运动和运动协调。在夜间循环期间，在Digiscan Animal Activity中测试动物的自发运动活动。老年动物表现出显着的活动减退相比，他们的年轻同行。对活动时间进程的评价显示，在12小时试验期间，幼龄动物具有周期性活动模式，在试验开始后2-4小时出现明显的峰值，此后间隔8- 10小时。相反，老年动物表现出钝化的初始活动峰。在试验期的剩余时间内，老年动物的活动稳定，没有进一步的活动峰值。与幼龄动物相比，老龄动物还（a）保持悬挂在水平钢丝上的时间更短，（B）无法以协调的方式从覆盖有钢丝网的木杆上下降，（c）从旋转杆上跌落的速度更快，（d）无法在一系列宽度不同的方形或圆形顶部的木梁上保持平衡。组织学分析表明，有没有减少的数量，面积或长度的酪氨酸羟化酶免疫反应神经元内的A8，A9，或A10区域的老年动物。神经化学分析表明，虽然DA和HVA水平没有降低，在老年大鼠的DOPAC水平，以及DA/DOPAC和DA/HVA的比例，下降。这些结果表明，黑质纹状体多巴胺能系统内的神经化学，而不是形态学的变化是老年大鼠运动行为缺陷的基础。
Spontaneous locomotion and motor coordination was evaluated in young (5-6 month old) and aged (24-25 month old) rats. Animals were tested for spontaneous locomotor activity in Digiscan Animal Activity Monitors during the nocturnal cycle. Aged animals exhibited a significant hypoactivity compared to their young counterparts. Evaluation of the time course of activity revealed that the young animals had a cyclical pattern of activity during the 12-hour testing period with clear peaks at 2-4 hours after the initiation of testing and at 8- to 10-hour intervals thereafter. In contrast, the aged animals exhibited a blunted initial activity peak. During the remainder of the test period the aged animals activity was stable with no further peaks in activity. Compared to the young animals the aged animals also (a) remained suspended from a horizontal wire for less time, (b) were unable to descend a wooden pole covered with wire mesh in a coordinated manner, (c) fell more rapidly from a rotating rod and (d) were unable to maintain their balance on a series of wooden beams with either a square or rounded top of varying widths. Histological analysis demonstrated that there was no reduction in the number, area, or length of tyrosine hydroxylase-immunoreactive neurons within the A8, A9, or A10 region of the aged animals. Neurochemical analysis revealed that while DA and HVA levels were not decreased in the aged rats, DOPAC levels, as well as the ratios of DA/DOPAC and DA/HVA, were decreased. These results indicate that neurochemical but not morphological changes within the nigrostriatal dopaminergic system underlie the deficits in motor behavior observed in aged rats.