研究人员发现，在纹状体中，乙酰胆碱释放神经元会诱导远端多巴胺轴突的动作电位发射。胆碱能神经元的自发活动产生的多巴胺释放超出了乙酰胆碱的信号域，并且在胆碱能激活的情况下，很容易从多巴胺轴突中记录到行进的动作电位。在自由运动的小鼠中，多巴胺和乙酰胆碱与运动方向有关。对烟碱型乙酰胆碱受体的局部抑制损害了多巴胺的动态，影响了运动。这些研究结果发现了一种独立于体细胞整合的动作电位启动的内源性机制，并确定这种机制在轴突和体细胞之间分离了对多巴胺信号的控制。
据悉，神经元的信息流通过整合树突中的输入，在体部附近产生动作电位，并从轴突中的神经终端释放神经递质来进行。
附：英文原文
Title: An action potential initiation mechanism in distal axons for the control of dopamine release
Author: Changliang Liu, Xintong Cai, Andreas Ritzau-Jost, Paul F. Kramer, Yulong Li, Zayd M. Khaliq, Stefan Hallermann, Pascal S. Kaeser
Issue&Volume: 2022-03-25
Abstract: Information flow in neurons proceeds by integrating inputs in dendrites, generating action potentials near the soma, and releasing neurotransmitters from nerve terminals in the axon. We found that in the striatum, acetylcholine-releasing neurons induce action potential firing in distal dopamine axons. Spontaneous activity of cholinergic neurons produced dopamine release that extended beyond acetylcholine-signaling domains, and traveling action potentials were readily recorded from dopamine axons in response to cholinergic activation. In freely moving mice, dopamine and acetylcholine covaried with movement direction. Local inhibition of nicotinic acetylcholine receptors impaired dopamine dynamics and affected movement. Our findings uncover an endogenous mechanism for action potential initiation independent of somatodendritic integration and establish that this mechanism segregates the control of dopamine signaling between axons and somata.
DOI: abn0532
Source: https://www.science.org/doi/10.1126/science.abn0532