Calcium-dependent desensitizing function of the postsynaptic neuronal-type nicotinic acetylcholine receptors at the neuromuscular junction.
Several subunits that commonly have been regarded as neuronal-type nicotinic acetylcholine receptor (nAChR) subtypes, have been found in the postjunctional endplate membrane of adult skeletal muscle fibres. The postsynaptic function of these neuronal-type nAChR subtypes at the neuromuscular junction has been investigated by using aequorin luminescence and fluorescence confocal imaging. A biphasic elevation of intracellular Ca2+ is elicited by prolonged nicotinic action at the mouse muscle endplates. The fast and slow Ca2+ components are operated by a postsynaptic muscle- and colocalized neuronal-type nAChR, respectively. Neuromuscular functions may be regulated by a dual nAChR system to maintain the normal postsynaptic excitability. Certain neuronal-type nAChR may be endowed with the same functional role in the central nervous system also.
Kimura
I
I
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Sugitani, Japan.
D000544:Alzheimer Disease / Q000503:physiopathology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000503:physiopathology; D006801:Humans; D018482:Muscle, Skeletal / Q000294:innervation / Q000378:metabolism / Q000502:physiology; D009468:Neuromuscular Diseases / Q000235:genetics / Q000503:physiopathology; D009469:Neuromuscular Junction / Q000502:physiology*; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000502:physiology; D011978:Receptors, Nicotinic / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013569:Synapses / Q000502:physiology*
D018015:Receptors, Calcitonin Gene-Related Peptide; D011978:Receptors, Nicotinic; D002118:Calcium