Campbell G A, Eckardt M J, Weight F F
Brain Res. 1985 May 6;333(2):261-70. doi: 10.1016/0006-8993(85)91580-x.
Afferent connections to the subthalamic nucleus (STN) were studied by microiontophoretically injecting horseradish peroxidase (HRP) into the STN and studying its retrograde transport. Remotely labelled neurons were frequently observed in both the globus pallidus and the pars compacta region of substantia nigra. In addition, individually labelled neurons were occasionally found in other brain regions. The sensitivity of neurons in the STN to dopamine (DA) was studied by applying DA to neurons in the STN by microiontophoresis. Three patterns of response to DA were observed. The most frequent response, observed in 46% of the STN neurons studied, was a decrease in the discharge frequency. In 15% of the neurons there was an increased frequency of firing. Eleven percent of the neurons exhibited a mixed response consisting of an initial depression of discharge rate followed by a delayed increase. The responses of STN neurons to DA were not antagonized by iontophoretically applied haloperidol. In neurons whose firing frequency was decreased by DA, the iontophoretic application of apomorphine and norepinephrine also decreased discharge rate. The observations of HRP-labelled neurons in the pars compacta region of substantia nigra following injection of HRP into the STN together with the DA responsiveness of STN neurons suggest the possibility of a dopaminergic nigro-subthalamic pathway.
通过向丘脑底核（STN）微量离子导入辣根过氧化物酶（HRP）并研究其逆向运输，来研究丘脑底核的传入连接。在苍白球和黑质致密部区域均频繁观察到远距离标记的神经元。此外，偶尔在其他脑区发现单个标记的神经元。通过微量离子导入法将多巴胺（DA）应用于丘脑底核的神经元，研究丘脑底核神经元对多巴胺的敏感性。观察到对多巴胺的三种反应模式。在所研究的46%的丘脑底核神经元中观察到最常见的反应是放电频率降低。15%的神经元放电频率增加。11%的神经元表现出混合反应，即放电率先初始降低，随后延迟增加。丘脑底核神经元对多巴胺的反应不受离子导入应用氟哌啶醇的拮抗。在放电频率因多巴胺而降低的神经元中，离子导入阿扑吗啡和去甲肾上腺素也会降低放电率。将HRP注入丘脑底核后在黑质致密部区域观察到HRP标记的神经元，以及丘脑底核神经元对多巴胺的反应性，提示存在多巴胺能黑质 - 丘脑底核通路的可能性。
