Department of Biology, University of Texas at San Antonio, San Antonio, TX, USA.
J Comput Neurosci. 2022 May;50(2):251-272. doi: 10.1007/s10827-022-00814-y. Epub 2022 Mar 11.
The external segment of globus pallidus (GPe) is a network of oscillatory neurons connected by inhibitory synapses. We studied the intrinsic dynamic and the response to a shared brief inhibitory stimulus in a model GPe network. Individual neurons were simulated using a phase resetting model based on measurements from mouse GPe neurons studied in slices. The neurons showed a broad heterogeneity in their firing rates and in the shapes and sizes of their phase resetting curves. Connectivity in the network was set to match experimental measurements. We generated statistically equivalent neuron heterogeneity in a small-world model, in which 99% of connections were made with near neighbors and 1% at random, and in a model with entirely random connectivity. In both networks, the resting activity was slowed and made more irregular by the local inhibition, but it did not show any periodic pattern. Cross-correlations among neuron pairs were limited to directly connected neurons. When stimulated by a shared inhibitory input, the individual neuron responses separated into two groups: one with a short and stereotyped period of inhibition followed by a transient increase in firing probability, and the other responding with a sustained inhibition. Despite differences in firing rate, the responses of the first group of neurons were of fixed duration and were synchronized across cells.
苍白球外部节段（GPe）是由抑制性突触连接的振荡神经元网络。我们在 GPe 网络模型中研究了其内在动态和对共享短暂抑制性刺激的反应。使用基于在切片中研究的小鼠 GPe 神经元测量的相位重置模型来模拟单个神经元。神经元在其发放率以及相位重置曲线的形状和大小方面表现出广泛的异质性。网络中的连接性设置为匹配实验测量值。我们在小世界模型中生成了具有统计等效神经元异质性的模型，其中 99%的连接是与近邻建立的，而 1%是随机建立的，而在具有完全随机连接性的模型中也是如此。在这两个网络中，局部抑制使静息活动变慢且变得更加不规则，但没有表现出任何周期性模式。神经元对之间的互相关仅局限于直接连接的神经元。当受到共享抑制性输入的刺激时，单个神经元的反应分为两组：一组表现为短暂的、刻板的抑制期，随后是发射概率的短暂增加，另一组则表现为持续抑制。尽管在发放率上存在差异，但第一组神经元的反应持续时间固定，并在细胞间同步。
