Behavioral Neuroscience, Department of Psychology, University of California, Los Angeles, CA 90095-1563, United States.
Behav Brain Res. 2011 Aug 10;221(2):488-98. doi: 10.1016/j.bbr.2009.12.046. Epub 2010 Jan 8.
There is a fundamental link between cholinergic neurotransmitter function and overt and covert actions. Major cholinergic systems include peripheral motor neurons organizing skeletal muscle movements into overt behaviors and cholinergic neurons in the basal forebrain and mesopontine regions that mediate covert actions realized as states of consciousness, arousal, selective attention, perception, and memory. Cholinergic interneurons in the striatum appear to integrate conscious and unconscious actions. Neural network models involving cholinergic neurons, as well as neurons using other neurotransmitters, emphasize connective circuitry as being responsible for both motor programs and neural correlates of higher consciousness. This, however, is only a partial description. At a more fundamental level lie intracellular mechanisms involving the cytoskeleton, which are common to both muscle contraction and neuroplastic responses in targets of central cholinergic cells attendant with higher cognition. Acetylcholine, acting through nicotinic receptors, triggers interactions between cytoskeletal proteins in skeletal muscle cells, as has been long known. There is also evidence that acetylcholine released at central sites acts through muscarinic and nicotinic receptors to initiate responses in actin and microtubule proteins. These effects and their implications for cholinergic involvement in higher cognition are explored in this review.
胆碱能神经递质功能与外显和内隐行为之间存在着根本联系。主要的胆碱能系统包括外周运动神经元，它们将骨骼肌运动组织成外显行为，以及基底前脑和中脑桥区域的胆碱能神经元，它们介导内隐行为，表现为意识状态、觉醒、选择性注意、知觉和记忆。纹状体中的胆碱能中间神经元似乎整合了有意识和无意识的行为。涉及胆碱能神经元的神经网络模型，以及使用其他神经递质的神经元，强调连接电路负责运动程序和高级意识的神经相关物。然而，这只是一个部分描述。在更基本的水平上，涉及细胞骨架的细胞内机制是共同的，既涉及肌肉收缩，也涉及伴随高级认知的中枢胆碱能细胞靶标中的神经可塑性反应。乙酰胆碱通过烟碱受体起作用，触发骨骼肌细胞中细胞骨架蛋白之间的相互作用，这一点早已为人所知。还有证据表明，中枢释放的乙酰胆碱通过毒蕈碱和烟碱受体作用于肌动蛋白和微管蛋白，引发反应。本文探讨了这些作用及其对胆碱能参与高级认知的影响。
