Voltage-activated sodium currents in acutely isolated mouse vestibular ganglion neurones.
Voltage-activated sodium currents (INa) in vestibular ganglion neurones acutely isolated from postnatal mice were investigated using the whole-cell configuration of the patch-clamp technique. Under recording conditions designed to allow the complete isolation of INa depolarizations from a holding potential of -80 mV revealed a fast inactivating inward current which was activated around -60 mV and exhibited maximum peak current around -30 mV. This current was eliminated when the cells were perifused with a Na(+)-free solution and almost totally blocked by application of 100 nM tetrodotoxin (TTX). These properties identify this inward current as TTX-sensitive INa. The half-maximum activation potential of INa was -46 mV and its half-maximum inactivation potential was -69 mV. This is the first report of voltage-activated sodium currents in vestibular primary neurones.
Chabbert
C
C
INSERM U432, Montpellier, France.
Chambard
J M
JM
Valmier
J
J
Sans
A
A
Desmadryl
G
G
D000818:Animals; D004553:Electric Conductivity; D005071:Evoked Potentials / Q000187:drug effects; D017950:Ganglia, Sensory / Q000166:cytology / Q000502:physiology*; D051379:Mice; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014725:Vestibular Nerve / Q000166:cytology / Q000502:physiology*
D015222:Sodium Channels; D013779:Tetrodotoxin