Sodium channels in primary sensory neurons: relationship to pain states.
Electrophysiological studies of dorsal root ganglion (DRG) neurons, and the results of PCR, Northern blot and in situ hybridization analyses have demonstrated the molecular diversity of Na+ channels that operate in sensory neurons. Several subtypes of alpha-subunit have been detected in DRG neurons and transcripts encoding all three beta-subunits are also present. Interestingly, one alpha subunit, Na(v)1.8, is selectively expressed in C-fibre and Adelta fibre associated sensory neurons that are predominantly involved in damage sensing. Another channel, Na(v).3, is selectively up regulated in a variety of models of neuropathic pain. In this review we focus on Na+ channels that are selectively expressed in DRG neurons as potential analgesic drug targets. In the absence of subtype specific inhibitors, the production of null mutant mice provides useful information on the specialized functions of particular Na+ channels. A refinement of this approach is to delete Na+ channel genes flanked by lox-P sites in the sensory ganglia of adult animals, using viruses to deliver the bacteriophage Cre recombinase enzyme.
Wood
John N
JN
Department of Biology, University College London, UK.
Akopian
Armen N
AN
Baker
Mark
M
Ding
Yanning
Y
Geoghegan
Fleur
F
Nassar
Mohammed
M
Malik-Hall
Misbah
M
Okuse
Kenji
K
Poon
Louisa
L
Ravenall
Samantha
S
Sukumaran
Madhu
M
Souslova
Veronika
V
D000818:Animals; D002874:Chromosome Mapping; D005727:Ganglia, Spinal / Q000503:physiopathology*; D005786:Gene Expression Regulation; D006801:Humans; D009475:Neurons, Afferent / Q000502:physiology*; D010146:Pain / Q000235:genetics / Q000503:physiopathology*; D015222:Sodium Channels / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology
D015222:Sodium Channels; D013779:Tetrodotoxin