Excitation of cultured murine dorsal root ganglion neurons by algesic substances and its suppression with low-power laser irradiation

Abstract

The exicitatory effects of algesic substances on cultured murine dorsal root ganglion (DRG) neurons were studied by measuring cytosolic calcium oscillations (conforcal laser scanning microscopy) and action potentials (patch-clamp whole-cell recording) in the cell body. Bradykinin, prostaglandin E₂, and capsaicin evoked action potentials in the cell body. Calcium oscillations were also observed by the stimulation of the compounds. Both the action potentials elicited and the elevation of calcium ion concentration caused by bradykinin were suppressed by the irradiation of Ga-Al-As diode laser (830nm, 16.2mW). The laser irradiation may block the depolarizations via sodium ion channels and calcium ion channels.