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Acetylcholine receptor channel subtype directs the innervation pattern of skeletal muscle
Author(s) -
Koenen Michael,
Peter Christoph,
Villarroel Alfredo,
Witzemann Veit,
Sakmann Bert
Publication year - 2005
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1038/sj.embor.7400429
Subject(s) - acetylcholine receptor , acetylcholine , skeletal muscle , microbiology and biotechnology , biology , receptor , anatomy , neuroscience , endocrinology , biochemistry
Acetylcholine receptors (AChRs) mediate synaptic transmission at the neuromuscular junction, and structural and functional analysis has assigned distinct functions to the fetal (α 2 βγδ) and adult types of AChR (α 2 βεδ). Mice lacking the ε‐subunit gene die prematurely, showing that the adult type is essential for maintenance of neuromuscular synapses in adult muscle. It has been suggested that the fetally and neonatally expressed AChRs are crucial for muscle differentiation and for the formation of the neuromuscular synapses. Here, we show that substitution of the fetal‐type AChR with an adult‐type AChR preserves myoblast fusion, muscle and end‐plate differentiation, whereas it substantially alters the innervation pattern of muscle by the motor nerve. Mutant mice form functional neuromuscular synapses outside the central, narrow end‐plate band region in the diaphragm, with synapses scattered over a wider muscle territory. We suggest that one function of the fetal type of AChR is to ensure an orderly innervation pattern of skeletal muscle.