Firing characteristics of two classes of neurons in rat DRG

    WANG Yuª²Ying, JIAN Zhong, WAN Yeª²Hong, HU Sanª²Jue

    Institute of Neuroscience of Chinese PLA, Fourth Military Medical University, Xi¡¯an 710033, China

    ¡¾Abstract¡¿ AIM: To study the characteristics of firing in rat dorsal root ganglia (DRG) neurons by neural excitability. METHODS: Wholeª²cell patchª²clamp experiments were performed with medium and small DRG neurons freshly isolated from rats. RESULTS: The firing characteristics of the two classes of cells were: In class 1, allª²orª²none action potentials could be generated with arbitrarily low frequency and the frequency increased with the increased current. No firing responded to weak inhibitory pulse. In class 2, the action potentials were generated in a certain frequency band that was relatively insensitive to the strength change of the applied current. Regular membrane potential oscillations emerged before and after firing, indicating spikes were not allª²orª²none, and postª²inhibitory spikes could be found. CONCLUSION: The two classes of rat DRG neurons have their own characteristics of firing. ......