Kita Hitoshi
Department of Anatomy and Neurobiology, The University of Tennessee Memphis, 855 Monroe Avenue, Memphis, TN 38163, USA.
Prog Brain Res. 2007;160:111-33. doi: 10.1016/S0079-6123(06)60007-1.
The external segment of the pallidum (GP(e)) is a relatively large nucleus located caudomedial to the neostriatum (Str). The GP(e) receives major inputs from two major basal ganglia input nuclei, the Str and the subthalamic nucleus (STN), and sends its output to many basal ganglia nuclei including the STN, the Str, the internal pallidal segment (GP(i)), and the substantia nigra (SN). Thus, the GPe can be placed at the center of the basal ganglia connection diagram (Fig. 1(A)). From the viewpoint that emphasizes the direct and indirect pathways of the basal ganglia, the GP(e) is a component of the indirect pathway that relays Str inputs to the STN. The indirect pathway can be traced in Fig. 1(A), although it comprises only a part of multiple indirect pathways. This chapter begins with a brief description of the anatomical organization of the GP(e) followed by physiological and pharmacological characterizations of GABAergic responses in the GP(e).
苍白球外侧部（GP(e)）是一个相对较大的核团，位于新纹状体（Str）的尾内侧。GP(e)主要接收来自两个主要基底神经节输入核团，即Str和丘脑底核（STN）的输入，并将其输出发送到许多基底神经节核团，包括STN、Str、苍白球内侧部（GP(i)）和黑质（SN）。因此，GPe可置于基底神经节连接图的中心（图1(A)）。从强调基底神经节直接和间接通路的角度来看，GP(e)是将Str输入传递至STN的间接通路的一个组成部分。间接通路可在图1(A)中追溯到，尽管它仅构成多个间接通路的一部分。本章首先简要描述GP(e)的解剖结构，随后介绍GP(e)中GABA能反应的生理和药理学特征。
