不同初级感觉神经元ATP-激活电流的特征及意义  

THE CHARACTERISTICS AND SIGNIFICANCES OF ATP-ACTIVATED CURRENTS IN DIFFERENT PRIMARY SENSORY NEURONS

作　　者：聂辉[1] 张玉芹[1] 程剑侠[1] 罗加烈[2] 李之望[2] 

机构地区：[1]武汉科技大学医学院生理学教研室,武汉430080 [2]华中科技大学同济医学院神经生物学系,武汉430030

出　　处：《神经解剖学杂志》2006年第5期517-520,共4页Chinese Journal of Neuroanatomy

基　　金：湖北省自然科学基金(No.2004ABA152)资助项目

摘　　要：为探讨大鼠不同初级感觉神经元ATP-激活电流的电生理学特征及意义,本实验在新鲜分离的大鼠三种初级感觉神经元标本上,应用全细胞膜片钳技术记录,对外加ATP引起的膜电流的变化进行了研究。结果显示:(1)受检的细胞绝大多数对ATP敏感,外加ATP记录到内向电流,在背根神经节和三叉神经节神经元记录到三种形式的ATP-激活电流:快速激活快速失活型(fasttype,F型)、快速激活缓慢失活型(intermediatetype,I型)和缓慢激活缓慢失活型(slowtype,S型),但在结状神经节神经元主要记录到S型电流,三种形式的电流均具有浓度依赖性;(2)三种形式的ATP-激活电流上升相(risingphase,R)从10%至90%的时间(R10-90)有明显差异(P<0.05),去敏感相(desensitizingphase)从10%至90%的时间(D10-90)也有明显差异(P<0.05);(3)三种形式的电流EC50非常接近,I型的量-效曲线居中间,F型的下移,S型的上移;(4)小细胞的ATP-激活电流多表现为F型特征,大细胞多表现为S型特征,而中等大小的细胞多表现为I型特征,结状神经节神经元电流形式与细胞大小没有相关性。以上结果提示:躯体和内脏初级感觉神经元ATP-激活电流的类型可能与不同的感觉性质有关;不同形式的ATP激活电流可能由ATP受体的不同亚单位组成的各种亚型中介。To explore the characteristics and significances of ATP-activated currents in rat different primary sensory neurons, the experiments were performed on neurons freshly isolated from rat dorsal root ganglion （DRG）, trigeminal ganglion （TG） and nodose ganglion （NG） using whole-cell patch-clamp. The results showed that： （ 1 ） The majority of examined neurons responded to ATP applied externally with inward currents. We recorded three types of ATP-activated currents in DRG and TG： fast type, slow type and intermediate type,while there was mainly slow type of ATP-activated currents in NG. All the three types of currents were concentration-dependent. （2） The rising phase time from 10% to 90% varied greatly among the three types of ATP-activated currents （P 〈 0.05 ） and the same thing occurred when it came to the desensitizing phase from 10% to 90% （ P 〈 0.05 ）. （3） The EC50 of the three dose-response curves of ATP-activated current tended to be identical. The curve for fast ATP-activated current shifted downwards as compared with the intermediate ATP-activated current, and that for the slow ATP-activated current shifted upwards. （4） In general, the fast ATP-activated currents were distributed mainly in small-diameter DRG and TG neurons; the slow ATP-activated currents were distributed mainly in large-diameter DRG and TG neurons; and the intermediate ATP-activated currents were distributed mainly in intermediate-diameter DRG and TG neurons; while the types of ATP-activated current recorded in NG neurons were not related to the diameter of a cell. The results suggest that three types of ATP-activated currents from different primary sensory neurons may be related to the properties of various senses; these types of ATP-activated current might be mediated by various subtypes of ATP receptors.

关 键 词：ATP-激活电流 离子型ATP受体 全细胞膜片钳 初级感觉神经元 大鼠 

分 类 号：R33[医药卫生—人体生理学]