猫扣带回前部内脏伤害感受神经元的膜电学特性

MEMBRANE ELECTRICAL PROPERTIES OF VISCERAL NOCICEPTIVE NEURONS IN ANTERIOR CINGULATE GYRUS OF CAT

目的 :研究猫扣带回前部内脏大神经刺激相关神经元的膜电生理特性 ,以便从神经元水平进一步了解大脑皮质内脏伤害感受的特性及机制 ,为痛觉理论“特异性学说”提供新的实验依据。方法 :应用在体玻璃微电极细胞内电位记录技术及细胞内注入极化电流的方法 ,测量和计算神经元的膜电学参数。结果 :将 2 0只猫扣带回前部 1 76个内脏大神经刺激相关神经元 ,分为内脏伤害 (1 4 8个 )和非伤害 (2 8个 )感受神经元。发现它们在膜电阻、时间常数、膜电容及I V曲线等方面存在差异。注入去极化电流引发的放电幅值及频率也存在差异。结论 :扣带回前部内脏伤害与非伤害感受神经元可能在细胞膜结构。

Aim:To explore the cerebral cortex mechanism of visceral nociceptive sensation and its characteristics on the cell level, we investigated the membrane electrical properties of 176 stimulus relative neurons of greater splanchnic nerve(GSN) in anterior cingulate gyrus(ACG) of 20 adult healthy cats.Methods:We used intracellular recording techniques of glass microelectrode and injected polarizing current into the neurons in ACG.Results:Among 176 neurons, 148 were visceral nociceptive neurons(VNNs) and 28 non visceral nociceptive neurons(NVNNs). The membrane resistance(Rm),time constant(τ), membrane capacity(Cm),and the I V curve of both VNNs and NVNNs in ACG were significantly different.The discharge frequency and amplitude of both VNNs and NVNNs produced by injecting depolarized current were different,too. Conclusion: The results suggest that structure of cell membrane,volume of the soma,and other aspects of morphology between VNNs and NVNNs in ACG may have significant differences. The results also might provide progressively experimental evidence for specific theory of pain sensation.