Postsynaptic nAChRs in the peripheral nervous system are critical for neuromuscular and autonomic neurotransmission. Pre- and peri-synaptic nAChRs in the brain modulate neurotransmission and are responsible for the addictive effects of nicotine. Subtypes of nAChRs in lymphocytes and non-synaptic locations may modulate inflammation and other cellular functions. All AChRs that function as ligand-gated ion channels are formed from five homologous subunits organized to form a central cation channel whose opening is regulated by ACh bound at extracellular subunit interfaces. nAChR subtype subunit composition can range from α7 homomers to α4β2α6β2β3 heteromers. Subtypes differ in affinities for ACh and other agonists like nicotine and in efficiencies with which their channels are opened and desensitized. Subtypes also differ in affinities for antagonists and for positive and negative allosteric modulators. Some agonists are “silent” with respect to channel opening, and AChRs may be able to signal metabotropic pathways by releasing G-proteins independent of channel opening. Electrophysiological studies that can resolve single-channel openings and molecular genetic approaches have allowed characterization of the structures of ligand binding sites, the cation channel, and the linkages between them, as well as the organization of AChR subunits and their contributions to function. Crystallography and cryo-electron-microscopy are providing increasing insights into the structures and functions of AChRs. However, much remains to be learned about both AChR structure and function, the in vivo functional roles of some AChR subtypes, and the development of better pharmacological tools directed at AChRs to treat addiction, pain, inflammation, and other medically important issues.

周围神经系统中的突触后 nAChR 对于神经肌肉和自主神经传递至关重要。大脑中突触前和突触周围的 nAChR 调节神经传递，并导致尼古丁的成瘾作用。淋巴细胞和非突触部位的 nAChR 亚型可能调节炎症和其他细胞功能。所有充当配体门控离子通道的 AChR 均由五个同源亚基组成，这些亚基组织形成一个中央阳离子通道，其开放受细胞外亚基界面上结合的 ACh 调节。nAChR 亚型亚基组成可以从 α7 同聚体到 α4β2α6β2β3 异聚体。亚型对乙酰胆碱和其他激动剂（如尼古丁）的亲和力以及其通道打开和脱敏的效率不同。亚型对拮抗剂以及正负变构调节剂的亲和力也不同。一些激动剂对于通道开放是“沉默的”，而 AChR 可能能够通过独立于通道开放释放 G 蛋白来向代谢途径发出信号。可以解决单通道开口问题的电生理学研究和分子遗传学方法可以表征配体结合位点、阳离子通道及其之间的连接的结构，以及 AChR 亚基的组织及其对功能的贡献。晶体学和冷冻电子显微镜使人们对 AChR 的结构和功能有了越来越深入的了解。然而，关于 AChR 的结构和功能、某些 AChR 亚型的体内功能作用，以及针对 AChR 治疗成瘾、疼痛、炎症和其他医学重要问题的更好药理学工具的开发，还有很多东西有待了解。