Shepard P D, German D C
Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235-9070.
Neuroscience. 1988 Nov;27(2):537-46. doi: 10.1016/0306-4522(88)90287-4.
The electrophysiological and pharmacological properties of dopaminergic neurons were systematically examined throughout the anterior-posterior extent of the substantia nigra zona compacta in the rat. Cells were characterized in terms of their (1) firing pattern, (2) firing rate, (3) antidromic response properties, and (4) inhibition in firing rate following dopaminergic agonist administration. These properties were then related to the cell's position within one of four anterior-posterior segments of the nucleus. There were three types of neuronal discharge pattern encountered; irregular, burst and regular. Cells which exhibited different firing patterns exhibited different firing rates and anatomical locations within the substantia nigra zona compacta. All neurons were antidromically activated from the striatum, however, the burst- and regular-firing cells exhibited significantly faster estimated conduction velocities than irregular-firing cells. The irregular-firing cells were most sensitive to dopaminergic autoreceptor agonists whereas the burst-firing cells were most sensitive to an indirect-acting dopaminergic agonist. These experiments provide both electrophysiological and pharmacological evidence to indicate that nigrostriatal dopaminergic neurons are composed of distinct subpopulations which are characterized by their firing pattern.
我们系统地研究了大鼠黑质致密部前后范围内多巴胺能神经元的电生理和药理学特性。根据细胞的(1)放电模式、(2)放电频率、(3)逆向反应特性以及(4)给予多巴胺能激动剂后放电频率的抑制情况对细胞进行了表征。然后将这些特性与细胞在核的四个前后节段之一中的位置相关联。共遇到三种神经元放电模式：不规则型、爆发型和规则型。表现出不同放电模式的细胞在黑质致密部内表现出不同的放电频率和解剖位置。所有神经元均能被来自纹状体的逆向激活，然而，爆发型和规则型放电细胞的估计传导速度明显快于不规则型放电细胞。不规则型放电细胞对多巴胺能自受体激动剂最为敏感，而爆发型放电细胞对间接作用的多巴胺能激动剂最为敏感。这些实验提供了电生理和药理学证据，表明黑质纹状体多巴胺能神经元由具有不同放电模式特征的不同亚群组成。
