皮层SI区伤害感受神经元膜电生理特性研究

Study of Electrical Properties of Membrane in Primary Sensory Cortex Nociceptive Neurons.

用细胞内记录技术， 在１６ 只成年健康猫， 研究了皮层第一躯体感觉区（ｐｒｉｍａｒｙ ｓｏｍａｔｏｓｅｎｓｏｒｙ ｃｏｒｔｅｘ ａｒｅａ ， Ｓ Ｉ区） 伤害感受神经元的电生理特性． Ｓ Ｉ区伤害感受神经元自发放电频率差异大， 放电形式多样． 极化电流绝对值≤１０ ｎ Ａ 时， 伤害感受神经元 Ｉ Ｖ极相关（ｒ ＝ ０９６） ， 整流作用不明显； 极化电流绝对值＞ １０ ｎ Ａ 时， 在两个方向上发生整流， Ｉ Ｖ （ 电流电压） 曲线表现为“ Ｓ”型， 其中伤害感受神经元整流作用较非伤害感受神经元明显． 伤害感受神经元 Ｒｍ 、τ、 Ｃｍ 明显大于非伤害感受神经元（ Ｐ＜ ００１ 或 Ｐ＜ ００５） ． 结果提示 Ｓ Ｉ区伤害感受神经元与非伤害感受神经元可能在细胞膜结构、细胞大小等方面存在有意义的差别， 从而反映其不同的生理功能．

In order to study function of the cortical nociceptive neurons(NCNs) on the cell level with intracellular recording and stereotaxic techniques,the electrical properties of their memberane were studied.The frequency of spontaneous discharges of the neurons were diverse obviously and revealed a variety of mode in discharge. When absolute value of polarization current was lesser than 1 0 nA,the relation of I V in NCNs was more significant( r =0 96) and the rectification insignificant;when the polarization current larger than 1 0 nA, the rectification occurred on both ends of the curve and then I V curve showed S type. The rectification of somatic NCNs was much significant than non nociceptive ones(NNCNs). R m, τ and C m of the NCNs were evidently larger than those of NNCNs( P <0 01 or P <0 05).The materials obtained indicated that morphology and structural of cell membrane,volume of the soma bettween NCNs and NNCNs might have meaningful differences. It also means that physiological functions were unlike. The specificity of the electrical parameters in cell membrane might provide experimental materials for specific theory of pain sensation. Reporting to investigate electrical properties( R m, τ and C m) of the membrane in primary cortial nociceptive neurons had not found in literatures.