The neuromuscular junction (NMJ) is a highly developed synapse linking motor neuron activity with muscle contraction. A complex of molecular cascades together with the specialized NMJ architecture ensures that each action potential arriving at the motor nerve terminal is translated into an action potential in the muscle fiber. The muscle-type nicotinic acetylcholine receptor (AChR) is a key molecular component located at the postsynaptic muscle membrane responsible for the generation of the endplate potential (EPP), which usually exceeds the threshold potential necessary to activate voltage-gated sodium channels and triggers a muscle action potential. Two AChR isoforms are found in mammalian muscle. The fetal isoform is present in prenatal stages and is involved in the development of the neuromuscular system whereas the adult isoform prevails thereafter, except after denervation when the fetal form is re-expressed throughout the muscle. This review will summarize the structural and functional differences between the two isoforms and outline congenital and autoimmune myasthenic syndromes that involve the isoform specific AChR subunits.

神经肌肉接头（NMJ）是高度发达的突触，将运动神经元活动与肌肉收缩联系在一起。复杂的分子级联以及专门的NMJ结构可确保到达运动神经末梢的每个动作电位都转化为肌肉纤维中的动作电位。肌肉型烟碱乙酰胆碱受体（AChR）是位于突触后肌膜的关键分子成分，负责端板电位（EPP）的产生，该终板电位通常超过激活电压门控钠通道并触发血管紧张素转换所需的阈值电位。肌肉动作电位。在哺乳动物肌肉中发现了两种AChR亚型。胎儿同工型存在于产前阶段，并参与神经肌肉系统的发育，而成年同工型随后盛行，除非去神经后在整个肌肉中重新表达胎儿型。这篇综述将总结两个同工型之间的结构和功能差异，并概述涉及同工型特异的AChR亚基的先天性和自身免疫性肌无力综合症。