Effect of aconitine on spontaneous activities from injured dorsal root ganglion neurons

    DUAN Jianª²Hong£¬YANG Ruiª²Hua£¬ HU Sanª²Jue

    PLA Institute of Neurosciences, School of Basic Medicine, Fourth Military Medical University£¬Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To study the effect of aconitine, an inhibitory blocker of inactivation gate of sodium channel, on the background firing with different patterns originating from injured dorsal root ganglion (DRG) neurons. METHODS: Ectopic spontaneous discharges originating from chronic compressed DRG neurons were recorded through single dorsal root fiber. The transformation and characteristics of interspike interval (ISI) series of firing induced by aconitine of type A neurons were observed and analyzed. RESULTS: It was found that after a 10 min bath of aconitine (10-200 ¦Ìmol/L) in L5 DRG, 80% neurons with bursting and 70% neurons with irregular pattern gradually changed into periodic pattern in injured DRG neurons, while 91% neuron with periodic pattern gradually increased in frequency but the pattern kept constant. Aconitine did not induce firing in resting neurons. CONCLUSION: Under the effect of aconitine, spontaneous activity in injured DRG neurons can change firing patterns. The effect of aconitine is in an activityª²dependent manner. ......