摘要
应用制霉菌素穿孔膜片钳全细胞记录技术研究了5－HT对急性分离的大鼠脊髓背角浅层（Ⅰ、Ⅱ层）神经元甘氨酸激活的全细胞电流的调控作用。实验结果表明：（1）在脊髓背角浅层神经元，甘氨酸作用于士的宁敏感型的甘氨酸受体，在钳制电位为-40mV时，可引起内向电流（IGly）；（2）5－HT呈浓度依赖性的增强Gly反应；（3）5－HT的增强作用既不改变IGly的平衡电位，也不影响Gly与受体的亲和力；（4）5－HT2受体激动剂α-甲基-5－HT能模拟5－HT的增强效应；而5－HT2受体的拮抗剂ketanserine可阻断5－HT对IGly的增强作用；（5）蛋白激酶C（PKC）的抑制剂chelerythrine可抑制5－HT对IGly的增强作用。本研究的结果说明：5－HT可呈浓度依赖性地增强大鼠脊髓背角浅层神经元的IGly，5－HT经5－HT2受体介导其对IGly的调控，脊髓背角浅层神经元内经PKC的信号转导途径在5－HT对IGly的增强效应中起重要的作用。本研究的结果提示5－HT和Gly的相互作用在脊髓水平的伤害性信息传递和调控过程中可能具有重要的意义。
Employing a nystatin-perforated patch-clamp whole-cell recording technique, we investigated the modulatory effects of serotonin (5-hydroxytryptamine, 5-HT) on glycine (Gly)-activated whole-cell currents (IGly) in neurons acutely dissociated from the superficial laminae (laminae Ⅰ and Ⅱ ) of the dorsal horn of the spinal cord in the rat. The results showed: (1) Gly acted on strychnine-sensitive Gly receptor and elicited inward currents at a holding potential (VH) of -40 mV; (2) 5-HT potentiated IGly in a concentration-dependent manner; (3) In the present of 5-HT, the reversal potentiation of Gly responses was not changed significantly, and the affinity of Gly to its strychnine-sensitive receptors was also not affected; (4) α-methyl-5-HT,which is the agonist of 5-HT2 receptor, mimicked the facilitating effect of 5-HT on IGly, whereas ketanserine, which is the antagonist of 5 HT2 receptor, blocked tile potentiation effect of 5-HT and failed to enhance IGly; (5) Chelerythrine, which is the inhibitor of protein kinase C (PKC), reduced the facilitating effects of 5-HT on IGly. The present results indicate: (1) 5-HT enhanced IGly, in a concentration-dependent manner in the superficial laminae neurons of the spinal dorsal horn in the rat; (2) The enhancement of 5-HT on IGly mediated through 5-HT2 receptor; (3) Intracellular signal transducting pathway through PKC is important to the facilitating effects of 5-HT on IGly. The present results suggest that the interactions between 5-HT and Gly might play an important role in the transmission and modulation of nociceptive information at spinal cord level.
出处
《神经解剖学杂志》
CSCD
北大核心
1998年第4期333-339,共7页
Chinese Journal of Neuroanatomy
基金
国家杰出人才基金
关键词
5-HT
甘氨酸
脊髓背角浅层
大鼠
全细胞电流
serotonin
glycine
nystatin-perforated patch-clamp whole-cell recording
superficial laminae of spinal dorsal horn
rat
