AN ACID SENSING ION-CHANNEL (ASIC) LOCALIZES TO SMALL PRIMARY AFFERENT NEURONS IN RATS

THE acid sensing ion channel (ASIC) identified in rat brain and spinal cord is potentially involved in the transmission of acid-induced noci ception. We have developed polyclonal antisera against ASIC, and used them to screen rat brain and spinal cord using immunocytochemistry. AS IC-immunoreactivity (-ir) is present in but not limited to the superfi cial dorsal horn, the dorsal root ganglia (DRG) and the spinal trigemi nal nucleus, as well as peripheral nerve fibers. These observations, c ombined with the disappearance of ASIC-ir following dorsal rhizotomy, suggest localization of ASIC to primary afferents. DRG ASIC-ir co-loca lizes with substance P (SP) and calcitonin gene-related peptide (CGRP) -ir in small capsaicin-sensitive cell bodies, suggesting that ASIC is poised to play a role in the transduction of noxious stimuli. (C) 1998 Rapid Science Ltd.