SUPPRESSIVE EFFECTS OF LOW-POWER LASER IRRADIATION ON BRADYKININ EVOKED ACTION-POTENTIALS IN CULTURED MURINE DORSAL-ROOT GANGLION-CELLS

The effects of Ga-Al-As diode laser (830 nm, 16.2 mW) irradiation on t he distal portion of the processes of cultured murine dorsal root gang lion (DRG) neurons associated with C-fibers were studied by patch-clam p whole-cell recording of membrane potentials at the cell body. The ch emical as well as laser light stimulations were limited to the process es of the neuron isolated from the cell body with a separator. The act ion potentials elicited by bradykinin (BK) in the cell body were rever sibly suppressed by the irradiation of laser light. The laser irradiat ion may block the conduction of nociceptive signals in primary afferen t neurons. The present experimental method offers a simple and easy to use procedure for studying the pain relief effects by laser irradiati on. (C) 1998 Elsevier Science Ireland Ltd.