TY  - JOUR
A1  - Wetzel, Andrea
A1  - Jablonka, Sibylle
A1  - Blum, Robert
T1  - Cell-autonomous axon growth of young motoneurons is triggered by a voltage-gated sodium channel
JF  - Channels (Austin)
N2  - Spontaneous electrical activity preceding synapse formation contributes to the precise regulation of neuronal development. Examining the origins of spontaneous activity revealed roles for neurotransmitters that depolarize neurons and activate ion channels. Recently, we identified a new molecular mechanism underlying fluctuations in spontaneous neuronal excitability. We found that embryonic motoneurons with a genetic loss of the low-threshold sodium channel Na\(_V\)1.9 show fewer fluctuations in intracellular calcium in axonal compartments and growth cones than wild-type littermates. As a consequence, axon growth of Na\(_V\)1.9-deficient motoneurons in cell culture is drastically reduced while dendritic growth and cell survival are not affected. Interestingly, Na\(_V\)1.9 function is observed under conditions that would hardly allow a ligand- or neurotransmitter-dependent depolarization. Thus, Na\(_V\)1.9 may serve as a cell-autonomous trigger for neuronal excitation. In this addendum, we discuss a model for the interplay between cell-autonomous local neuronal activity and local cytoskeleton dynamics in growth cone function.
KW  - spontaneous excitation
KW  - spinal muscular atrophy
KW  - axon growth
KW  - sodium channel
KW  - motoneurons
KW  - local protein synthesis
KW  - NaV1.9
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132586
VL  - 7
IS  - 1
ER  -