Bayasgalan Tsogbadrakh, Csemer Andrea, Kovacs Adrienn, Pocsai Krisztina, Pal Balazs
Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Front Cell Neurosci. 2021 Feb 25;15:614947. doi: 10.3389/fncel.2021.614947. eCollection 2021.
Dorsal and median raphe nuclei (DR and MR, respectively) are members of the reticular activating system and play important role in the regulation of the sleep-wakefulness cycle, movement, and affective states. M-current is a voltage-gated potassium current under the control of neuromodulatory mechanisms setting neuronal excitability. Our goal was to determine the proportion of DR and MR serotonergic neurons possessing M-current and whether they are organized topographically. Electrophysiological parameters of raphe serotonergic neurons influenced by this current were also investigated. We performed slice electrophysiology on genetically identified serotonergic neurons. Neurons with M-current are located rostrally in the DR and dorsally in the MR. M-current determines firing rate, afterhyperpolarization amplitude, and adaptation index (AI) of these neurons, but does not affect input resistance, action potential width, and high threshold oscillations.These findings indicate that M-current has a strong impact on firing properties of certain serotonergic neuronal subpopulations and it might serve as an effective contributor to cholinergic and local serotonergic neuromodulatory actions.
背侧和中缝核（分别为DR和MR）是网状激活系统的组成部分，在睡眠-觉醒周期、运动和情感状态的调节中发挥重要作用。M电流是一种受神经调节机制控制的电压门控钾电流，可调节神经元兴奋性。我们的目标是确定具有M电流的DR和MR5-羟色胺能神经元的比例，以及它们是否按拓扑结构排列。我们还研究了受该电流影响的中缝5-羟色胺能神经元的电生理参数。我们对基因鉴定的5-羟色胺能神经元进行了脑片电生理学研究。具有M电流的神经元位于DR的前部和MR的背侧。M电流决定了这些神经元的放电频率、超极化后电位幅度和适应指数（AI），但不影响输入电阻、动作电位宽度和高阈值振荡。这些发现表明，M电流对某些5-羟色胺能神经元亚群的放电特性有强烈影响，它可能是胆碱能和局部5-羟色胺能神经调节作用的有效贡献者。
