First published online May 9, 2008
Development 135, 1103e (2008)
© The Company of Biologists Limited
The muscle behind synaptic patterning
During the innervation of mammalian muscles, neuromuscular (NM) synapses
form at specific sites on muscle fibres. For years, it has been thought that
ingrowing nerves determine these synaptic sites. However, on
p. 1957, Liu and
colleagues challenge this `neurocentric' view by reporting that the
-subunit of the acetylcholine receptor (AChR), which is expressed in
embryonic muscle but is replaced after birth by the 
-subunit, plays an
essential role in NM synaptic patterning. In wild-type mice, pre-patterned
AChR clusters form on muscle cells early in NM synaptogenesis but their
subsequent role in synapse development is unclear. The researchers show that
deletion of the AChR -subunit gene delays the formation of these
clusters, which are also more broadly distributed than normal. Furthermore,
the presynaptic nerves in the -null mice contact a broader region of
the muscle than those in wild-type mice. These results indicate that the AChR
-subunit is required for the formation of pre-patterned AChR clusters,
which, in turn, determine the pattern of NM synaptogenesis.
Related articles in Development:
- Essential roles of the acetylcholine receptor -subunit in neuromuscular synaptic patterning
- Yun Liu, Daniel Padgett, Masazumi Takahashi, Hongqiao Li, Ayaz Sayeed, Russell W. Teichert, Baldomero M. Olivera, Joseph J. McArdle, William N. Green, and Weichun Lin
Development 2008 135: 1957-1967.
[Abstract]
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