Lamour Y, Dutar P, Jobert A
Neuroscience. 1985 Dec;16(4):835-44. doi: 10.1016/0306-4522(85)90097-1.
The properties of cortical cerebral neurons have been studied and compared in 2, 22 and 26 month-old Sprague-Dawley rats, using electrophysiological techniques. The mean spontaneous activity of the neurons in old animals (unidentified as well as pyramidal tract neurons) was not different from that of young adult rats. In contrast the mean latency of the antidromic response of pyramidal tract neurons to pyramidal tract stimulation was significantly longer in 26 month-old animals. No difference was observed in the effects of the excitatory amino acid glutamate applied by iontophoresis. The percentage of cortical neurons excited by the iontophoretic application of acetylcholine was similar in young and old animals. Neither the laminar distribution, nor the individual sensitivity of these neurons to acetylcholine were found to be modified. The pharmacological properties of the acetylcholine-induced excitations were unchanged, exhibiting muscarinic as well as nicotinic properties. These results are consistent with the suggestion that the impairment of the cholinergic system with aging is for a large part presynaptic. They also emphasize the fact that several physiological and pharmacological properties of the cerebral cortical neurons show little change with age in Sprague-Dawley rats.
利用电生理技术，对2月龄、22月龄和26月龄的斯普拉格-道利大鼠大脑皮质神经元的特性进行了研究和比较。老年动物（未识别神经元以及锥体束神经元）中神经元的平均自发活动与年轻成年大鼠并无差异。相比之下，26月龄动物中锥体束神经元对锥体束刺激的逆向反应平均潜伏期明显更长。离子导入施加兴奋性氨基酸谷氨酸的效果未观察到差异。离子导入乙酰胆碱所兴奋的皮质神经元百分比在年轻和老年动物中相似。这些神经元的层状分布及其对乙酰胆碱的个体敏感性均未发现改变。乙酰胆碱诱导兴奋的药理学特性未变，表现出毒蕈碱样以及烟碱样特性。这些结果与以下观点一致，即随着年龄增长胆碱能系统的损害在很大程度上是突触前的。它们还强调了这样一个事实：在斯普拉格-道利大鼠中，大脑皮质神经元的若干生理和药理学特性随年龄变化很小。
