Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Amsterdam, VU University Amsterdam, Amsterdam, Netherlands.
Front Neural Circuits. 2017 Dec 8;11:100. doi: 10.3389/fncir.2017.00100. eCollection 2017.
Acetylcholine (ACh) signaling shapes neuronal circuit development and underlies specific aspects of cognitive functions and behaviors, including attention, learning, memory and motivation. During behavior, activation of muscarinic and nicotinic acetylcholine receptors (mAChRs and nAChRs) by ACh alters the activation state of neurons, and neuronal circuits most likely process information differently with elevated levels of ACh. In several brain regions, ACh has been shown to alter synaptic strength as well. By changing the rules for synaptic plasticity, ACh can have prolonged effects on and rearrange connectivity between neurons that outlasts its presence. From recent discoveries in the mouse, rat, monkey and human brain, a picture emerges in which the basal forebrain (BF) cholinergic system targets the neocortex with much more spatial and temporal detail than previously considered. Fast cholinergic synapses acting on a millisecond time scale are abundant in the mammalian cerebral cortex, and provide BF cholinergic neurons with the possibility to rapidly alter information flow in cortical microcircuits. Finally, recent studies have outlined novel mechanisms of how cholinergic projections from the BF affect synaptic strength in several brain areas of the rodent brain, with behavioral consequences. This review highlights these exciting developments and discusses how these findings translate to human brain circuitries.
乙酰胆碱 (ACh) 信号塑造神经元回路的发育，并为认知功能和行为的特定方面提供基础，包括注意力、学习、记忆和动机。在行为过程中，ACh 通过激活毒蕈碱型和烟碱型乙酰胆碱受体 (mAChRs 和 nAChRs) 改变神经元的激活状态，并且神经元回路很可能以不同的方式处理信息，因为 ACh 水平升高。在几个脑区中，已经证明 ACh 可以改变突触强度。通过改变突触可塑性的规则，ACh 可以对神经元之间的连接进行长时间的影响和重新排列，这种影响持续时间超过其存在时间。从最近在小鼠、大鼠、猴子和人类大脑中的发现中，可以看出基底前脑 (BF) 胆碱能系统以前所未有的空间和时间细节靶向新皮质。作用于毫秒时间尺度的快速胆碱能突触在哺乳动物大脑皮层中大量存在，为 BF 胆碱能神经元提供了快速改变皮质微回路信息流的可能性。最后，最近的研究概述了 BF 的胆碱能投射影响几种啮齿动物大脑脑区突触强度的新机制，并具有行为后果。这篇综述强调了这些令人兴奋的发展，并讨论了这些发现如何转化为人类大脑回路。
