Ishida Yoshiyuki, Okawa Yayoi, Ito Sachiko, Shirokawa Tetsuya, Isobe Ken-Ichi
Radioisotope Research Center, Nagoya University Graduate School of Medicine, Japan.
Neurosci Lett. 2007 May 18;418(3):257-61. doi: 10.1016/j.neulet.2007.03.031. Epub 2007 Mar 19.
Age-dependent changes in dopaminergic (DA) innervation of the neostriatum (Str) were studied in male F344/N rats. Projections from the substantia nigra pars compacta (SNc) to the neostriatum were quantified using electrophysiological methods at age points from 6 to 24 months. The percentage of DA neurons activated antidromically by electrical stimulation (P-index) of Str increased between 18 and 24 months. Additionally, the percentage of DA neurons showing multiple antidromic latencies from striatal stimulation (M-index), which suggests axonal branching of individual DA neurons, increased significantly between 6 and 12 months and 6 and 24 months. These results suggest that DA neurons exhibit increased axonal branching in the aged brain.
在雄性F344/N大鼠中研究了新纹状体（Str）多巴胺能（DA）神经支配的年龄依赖性变化。使用电生理方法在6至24个月的年龄点对从黑质致密部（SNc）到新纹状体的投射进行定量。通过Str的电刺激（P指数）逆向激活的DA神经元百分比在18至24个月之间增加。此外，显示来自纹状体刺激的多个逆向潜伏期的DA神经元百分比（M指数），这表明单个DA神经元的轴突分支，在6至12个月以及6至24个月之间显著增加。这些结果表明，DA神经元在老年大脑中表现出轴突分支增加。
