Department of Neuroscience, Karolinska Institutet, Stockholm 17177, Sweden.
Neuron. 2021 Feb 3;109(3):516-529.e4. doi: 10.1016/j.neuron.2020.11.006. Epub 2020 Nov 27.
The rodent external globus pallidus (GPe) contains two main neuronal subpopulations, prototypic and arkypallidal cells, which differ in their cellular properties. Their functional synaptic connectivity is largely unknown. Here we studied the membrane properties, synaptic inputs, and sensory responses of these subpopulations in the mouse GPe. We performed in vivo whole-cell recordings in GPe neurons and used optogenetic stimulation to dissect their afferent inputs from the striatum and subthalamic nucleus (STN). Both GPe subpopulations received barrages of excitatory and inhibitory inputs during slow wave activity and responded to sensory stimulation with distinct multiphasic patterns. Prototypic cells synaptically inhibited arkypallidal and prototypic cells. Both GPe subpopulations received synaptic input from STN and striatal medium spiny neurons (MSNs). Although STN and indirect pathway MSNs strongly targeted prototypic cells, direct pathway MSNs selectively inhibited arkypallidal cells. We show that GPe subtypes have distinct connectivity patterns that underlie their respective functional roles.
啮齿动物的外苍白球（GPe）包含两种主要的神经元亚群，典型细胞和 arkypallidal 细胞，它们在细胞特性上有所不同。它们的功能突触连接在很大程度上是未知的。在这里，我们研究了小鼠 GPe 中这些亚群的膜特性、突触输入和感觉反应。我们在 GPe 神经元中进行了体内全细胞记录，并使用光遗传学刺激来剖析它们来自纹状体和丘脑底核（STN）的传入输入。在慢波活动期间，两种 GPe 亚群都接收到兴奋性和抑制性输入的弹幕，并对感觉刺激产生独特的多相模式作出反应。典型细胞突触抑制 arkypallidal 细胞和典型细胞。两种 GPe 亚群都接收来自 STN 和纹状体中间神经元（MSNs）的突触输入。尽管 STN 和间接通路 MSNs 强烈靶向典型细胞，但直接通路 MSNs 选择性地抑制 arkypallidal 细胞。我们表明，GPe 亚型具有不同的连接模式，这是它们各自功能作用的基础。
