The external globus pallidus (GP) firing rate synchronizes the basal ganglia-thalamus-cortex network controlling GABAergic output to different nuclei. In this context, two findings are significant: the activity and GABAergic transmission of the GP modulated by GABA B receptors and the presence of the GP-thalamic reticular nucleus (RTn) pathway, the functionality of which is unknown. The functional participation of GABA B receptors through this network in cortical dynamics is feasible because the RTn controls transmission between the thalamus and cortex. To analyze this hypothesis, we used single-unit recordings of RTn neurons and electroencephalograms of the motor cortex (MCx) before and after GP injection of the GABA B agonist baclofen and the antagonist saclofen in anesthetized rats. We found that GABA B agonists increase the spiking rate of the RTn and that this response decreases the spectral density of beta frequency bands in the MCx. Additionally, injections of GABA B antagonists decreased the firing activity of the RTn and reversed the effects in the power spectra of beta frequency bands in the MCx. Our results proved that the GP modulates cortical oscillation dynamics through the GP-RTn network via tonic modulation of RTn activity.

中文翻译：

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苍白球 GABA B 受体：参与皮质 β 动力学和丘脑网状核活动

外部苍白球 (GP) 放电率同步控制 GABAergic 输出到不同核的基底神经节-丘脑-皮质网络。在这种情况下，有两个重要发现：由 GABA B 受体调节的 GP 的活性和 GABA 能传递，以及 GP 丘脑网状核 (RTn) 通路的存在，其功能未知。GABA B 受体通过该网络参与皮层动力学是可行的，因为 RTn 控制丘脑和皮层之间的传输。为了分析这一假设，我们在麻醉大鼠中使用 GABA B 激动剂巴氯芬和拮抗剂沙氯芬 GP 注射前后的 RTn 神经元和运动皮层 (MCx) 脑电图的单单位记录。我们发现 GABA B 激动剂增加了 RTn 的峰值速率，并且这种响应降低了 MCx 中 β 频带的频谱密度。此外，注射 GABA B 拮抗剂会降低 RTn 的放电活性，并逆转 MCx 中 β 频带功率谱的影响。我们的结果证明，GP 通过 RTn 活动的强直调制通过 GP-RTn 网络调节皮质振荡动力学。