Plasticity of TTX-sensitive sodium channels PNI and brain III in injured human nerves

Sensory neurones co-express voltage-gated sodium channels that mediate TTX- sensitive (TTX-S) and TTX-resistant (TTX-R) currents, which may contribute to chronic pain after nerve injury. We previously demonstrated that TTX-R c hannels were decreased acutely in human sensory cell bodies after central a xotomy, but accumulated in nerve terminals after peripheral axotomy. We hav e now studied the TTX-S channels PNI and Brain III, using specific antibodi es for immunohistochemistry, in dorsal root ganglia (DRG) from 10 patients with traumatic central axotomy, nerves from 16 patients with peripheral axo tomy, and controls. PNI showed temporal changes similar to the TTX-R channe ls in sensory cell bodies of injured DRG. In contrast, Brain III was found only in injured nerves (not control nerves, or control/central axotomy DRG) . PNI and Brain III are distinct targets for novel analgesics. NeuroReport 12:495-500 (C) 2001 Lippincott Williams & Wilkins.