The alpha-7 nicotinic receptor, also known as the α7 receptor, is a type of nicotinic acetylcholine receptor implicated in long-term memory, consisting entirely of α7 subunits.[1] As with other nicotinic acetylcholine receptors, functional α7 receptors are pentameric [i.e., (α7)5 stoichiometry].
It is located in the brain, spleen, and lymphocytes of lymph nodes where activation yields post- and presynaptic excitation,[1] mainly by increased Ca2+ permeability.
Further, recent work has implicated this receptor as being important for generation of adult mammal neurons in the retina.[2] Functional α7 receptors are present in the submucous plexus neurons of the guinea-pig ileum.[3]
Recent work has demonstrated a potential role in reducing inflammatory neurotoxicity in stroke, myocardial infarction, sepsis, and Alzheimer's disease.[4][5][6]
An α7 nicotinic agonist appears to have positive effects on neurocognition in persons with schizophrenia.[7]
Activation of α7 nicotinic acetylcholine receptor on mast cells, is a mechanism by which nicotine enhances atherosclerosis.[8]
Both α4β2 and α7 nicotinic receptors appear to be critical for memory, working memory, learning, and attention.[9]
α7-nicotinic receptors also appear to be involved in cancer progression. They have been shown to mediate cancer cell proliferation and metastasis.[10] α7 receptors are also involved in angiogenic and neurogenic activity, and have anti-apoptotic effects.[11][12][13]
At least two types of positive allosteric modulators (PAMs) can be distinguished.[29]
It is found that anandamide and ethanol cause an additive inhibition on the function of α7-receptor by interacting with distinct regions of the receptor. Although ethanol inhibition of the α7-receptor is likely to involve the N-terminal region of the receptor, the site of action for anandamide is located in the transmembrane and carboxyl-terminal domains of the receptors.[38]
