First published online October 30, 2006
Development 133, 2203e (2006)
© The Company of Biologists Limited
For plastic synapses - start recycling
Synaptic connections in the mammalian nervous system are established during
development but are refined during adult life. In the CNS, synaptic plasticity
is partly regulated by recycling postsynaptic neurotransmitter receptors.
Bruneau and Akaaboune now describe the dynamics of acetylcholine receptor
(AChR) recycling at the neuromuscular junction (NMJ) in mice and reveal that
tyrosine dephosphorylation controls the insertion and maintenance of recycled
AChR at this accessible synapse (see
p. 4485). Previously,
the researchers had shown, by using biotin-bungarotoxin and labelled
streptavidin, that many AChRs reappear in the postsynaptic membrane after
internalization and intermingle with AChRs that have not been internalized -
so-called pre-existing AChRs. Now they show that recycled AChRs are removed
from functional synapses much faster than pre-existing receptors. Denervation
of the NMJ increases their removal rate; conversely, muscle stimulation
prevents their loss. These findings shed light on how receptors at less
accessible synapses are recycled and thus how synaptic plasticity is regulated
in the CNS.
Related articles in Development:
- The dynamics of recycled acetylcholine receptors at the neuromuscular junction in vivo
- Emile G. Bruneau and Mohammed Akaaboune
Development 2006 133: 4485-4493.
[Abstract]
[Full Text]