THE IMPORTANCE OF ION CHANNELS FOR MACROPHAGE AND MICROGLIAL ACTIVATION IN-VITRO

Microglia, the resident macrophages of the central nervous system (CNS ), are activated rapidly in response to neuronal injury. In the search for factors which regulate inflammation resulting from pathology in t he CNS, it is logical to focus on changes in the local environment whi ch occur following neuronal death. These include transient alterations in transmembrane ion gradients. Electrophysiological studies have pro vided information on the range of ion channels expressed by macrophage s and microglia in vitro. The purpose of this study was to focus on th e biology of macrophages and the role ion channels play in determining their activity. We show that potassium channels are unlikely to be in volved in the generation of nitric oxide by activated macrophages and microglial cell lines in vitro. Chloride channels are more likely to c ontribute to this response. Our results question the functional import ance of the observed differences between the channel expression in vit ro of macrophages and microglia. (C) 1998 Wiley-Liss, Inc.