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Differential muscle‐driven synaptic remodeling in the neuromuscular junction after denervation
Author(s) -
Yampolsky Pessah,
Pacifici Pier Giorgio,
Witzemann Veit
Publication year - 2010
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2010.07096.x
Subject(s) - denervation , neuromuscular junction , postsynaptic potential , acetylcholine receptor , receptor , microbiology and biotechnology , biology , neuroscience , motor endplate , green fluorescent protein , neurotransmission , chemistry , anatomy , biochemistry , gene
We used knock‐in mice that express green fluorescent protein (GFP)‐labeled embryonic‐type acetylcholine receptors to investigate postsynaptic responses to denervation of fast‐twitch and slow‐twitch muscle fibers, and to visualize the integration of newly synthesized GFP‐labeled embryonic‐type receptors into adult synapses. The embryonic‐type receptors are transiently expressed and incorporated into the denervated endplates. They replaced synaptic adult‐type receptors in a directed fashion, starting from the endplate’s periphery and proceeding to its central regions. The progress of embryonic‐type receptor expression with respect to transcriptional control is a transient, short‐term activation mechanism. The less pronounced increase in the expression levels of the GFP‐labeled receptors revealed a differential shift in the integration and degradation processes that constitute the dynamic equilibrium of the synaptic receptor pool. Therefore, we were able to model the changes in the total receptor load of the neuromuscular endplate following denervation as a function of the abundance of available receptors and the initial receptor load of the endplate.