大鼠受损背根节中型感觉神经元的温度敏感性

THERMOSENSITIVITY OF INJURED DORSAL ROOT GANGLION MEDIUM NEURONS IN RATS

摘要:

目的：观察大鼠损伤背根节（DRG）中型感觉神经元的热温度敏感性。方法：在急性离散的大鼠DRG中型神经元上,运用全细胞膜片钳技术,观察不同温度梯度刺激下受损DRG神经元的放电的特征。结果：大鼠损伤DRG中型神经元与热温度变化有一定的关系,它们根据放电模式可分为3型,其中62%（26/42）的中型神经元与热温度变化密切相关,随着温度的升高而引发的逐渐增强的膜电位去极化可引发频率由低到高的动作电位。随着温度的降低神经元又表现出频率由高到低的动作电位变化,放电后有规律的膜电位振荡,于较弱的超极化刺激可产生反跳动作电位,动作电位的幅值不一致。该类神经元具有电压依赖性。结论：大鼠受损DRG中型感觉神经元特别是紧张型放电的神经元对非伤害性刺激反应强烈,具有热温度敏感性。

Abstract:

Objective: To investigate the effects of temperature on injured dorsal root ganglia(DRG) neurons in rats.Methods: Whole-cell patch clamp recording was performed with injured DRG neurons freshly isolated from rats.Results: The injured medium sensory neurons were warm-sensitive.There were three type firing patterns in this neurons: tonic-firing,bursting firing,single spiking.In tonic-firing neuron,the number of spikes and the frequency increased with increases of the temperature,and vice versa.Regular membrane potential oscillations emerged after firing,indicating spikes were not all-or-none,and post-inhibitory spikes could be found.The warm-sensitive neurons were voltage dependent.Conclusion: The injured DRG sensory neurons have warmsensitivity.