Watanabe H
Exp Gerontol. 1987;22(1):17-25. doi: 10.1016/0531-5565(87)90011-8.
The purpose of this study was to investigate the in vivo rate of dopamine (DA) synthesis in dopaminergic neurons of the brain related to motor disturbances observed in aged rats. Aged rats of both sexes showed a decrease in spontaneous motor activity during a dark period as compared with those of mature rats. The in vivo rate of DA synthesis, as reflected in DOPA accumulation, in the striatum and nucleus accumbens, was slower in aged than in mature rats, whereas in the olfactory tubercle there was no significant difference between them. This suggests a differential vulnerability of dopaminergic neurons in the extrapyramidal motor areas of aged animals. After DA receptor blockade by haloperidol, increases in DA synthesis in the striatum, nucleus accumbens and olfactory tubercle were similar in both aged and mature rats, suggesting that there may be no age-related change in inhibitory regulation of in vivo DA synthesis mediated by presynaptic DA autoreceptors and/or a neuronal feedback mechanism via postsynaptic DA receptors in the striatum and mesolimbic DA regions.
本研究的目的是调查与老年大鼠所观察到的运动障碍相关的脑内多巴胺能神经元中多巴胺（DA）的体内合成速率。与成年大鼠相比，老年雌雄大鼠在黑暗期的自发运动活动减少。纹状体和伏隔核中，以多巴积累反映的DA体内合成速率在老年大鼠中比成年大鼠慢，而在嗅结节中两者之间无显著差异。这表明老年动物锥体外系运动区域中多巴胺能神经元的易损性存在差异。用氟哌啶醇阻断DA受体后，老年大鼠和成年大鼠纹状体、伏隔核及嗅结节中DA合成的增加相似，这表明在纹状体和中脑边缘DA区域，由突触前DA自身受体介导的体内DA合成的抑制调节和/或经由突触后DA受体的神经元反馈机制可能不存在与年龄相关的变化。
