SELECTIVE LOSS OF SLOW AND ENHANCEMENT OF FAST NA+ CURRENTS IN CUTANEOUS AFFERENT DORSAL-ROOT GANGLION NEURONS FOLLOWING AXOTOMY

NEUROBIOLOGY OF DISEASE

卷:2

Article

RIZZO, MA ; KOCSIS, JD ; WAXMAN, SG

关键词: AXOTOMY;    SODIUM CURRENT;    SODIUM CHANNELS;    NERVE INJURY;    AXON;    PATCH-CLAMP;    TETRODOTOXIN;   

DOI  :  10.1006/nbdi.1995.0009

来源: Elsevier

【 摘 要 】

Voltage-dependent Na+ currents were recorded via patch-clamp from identified adult rat lumbar cutaneous dorsal root ganglion (DRG) neurones using whole-cell and bleb-patch-clamp configurations. Na+ currents in DRG neurones studied 18 days after sciatic nerve ligation were compared with those in control neurones. Control neurones tended to have a singular kinetically slow Na+ current or net Na+ current suggestive of two kinetic varieties of channel in a single neurone. Three changes occurred following axotomy: (1) the peak Na+ current increased significantly, (2) kinetically slow TTX-resistant Na+ current, which predominated in controls, was significantly attenuated or lacking altogether, and (3) a singular, TTX-sensitive kinetically fast form of Na+ current predominated. These findings suggest that as part of the response to axonal injury, DRG neurones increase Na+ channel biosynthesis and/or modify preexisting channels such that their kinetics are accelerated. The results are consistent with the idea that axotomized DRG neurones become hyperexcitable due to the emergence of a high density of kinetically fast, pharmacologically distinguishable, Na+ channels in the membrane.

【 授权许可】

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