大鼠大脑皮质神经元一种新型去极化电位  

A NEW TYPE OF DEPOLARIZATION POTENTIALS IN RAT NEOCORTEX

作　　者：史明仪[1] 周华珠[1] 闫丽萍 

机构地区：[1]扬州大学医学院生理教研室

出　　处：《神经科学》1996年第1期13-18,共6页Chinese Journal of Neuroscience

摘　　要：５—ＨＴ灌流大鼠脑片并刺激丘脑内髓板时，２４．３％的大脑皮质额叶后部Ⅳ层神经元出现一种阵发性的潜伏期长、幅度大的会极化电位（Ｌａｒｇｅｄｅｐｏｌａｒｉｚａｔｉｏｎｐｏｔｅｎｔｉａｌ，ＬＤＰ）。５－ＨＴ１Ｂ激动剂ＴＦＭＰＰ、ＧＡＢＡＡ拮抗剂ｂｉｃｕｃｕｌｌｉｎｅ灌流并刺激内髓板时，也有类似诱发效应、ＬＤＰ伴膜电阻降低，随胞膜超极化而幅度增大，去极化而减小，其平衡电位近似钠平衡电位。ＬＤＰ为５－ＨＴ１拮抗剂Ｍｅｔｈｉｏｔｈｅｐｉｎ所抑制，几乎不受５－ＴＨ１ｃ／２、５—ＨＴ。拮抗剂Ｋｅｔａｎｓｅｒｉｎｅ、ＭＤＬ—７２２２２以及ＮＭＤＡ、非ＮＭＤＡ拮抗剂ＡＰＶ、ＤＮＱＸ所影响。提示ＬＤＰ可能与钠内流有关，是一种不同于已知突触电位的新发现电位，可能与丘脑－皮质非特异投射有关。With 5-HT perfusion and stimulation of the medial medullar lamima, 24.3% neurons in rat cortsx slices generatsd a volley of depolarizations with long letency and high amplitude, which also occurred during perfusion of 5-HT1B agonist TFMPP or GABA. antagonist bicuculline and was inhibited by 5-HT1 antagonist methiothepin. 5-HT1c/2, 5-HT3 receptor antagonists ketanserine, MDL-72222 or NMDA, non-NMDA receptor antagonists APV, DNQX had no effect on it. The depolarization was accompanied by a decrease in membrane resistance, and was enhanced and attenuated upon conditioning hyperpolarization and depolarization respectively. The extrapolated reversal pot6ntial was 34 mv. These results suggested that an activation of sodium conductance was probably involved in genesis of the depolarization, which was different from all known synaptic potentials and may be related to the non-specific projection system from thalamus to cortex.

关 键 词：皮质 突触电位 去极化 

分 类 号：R338.8[医药卫生—人体生理学] R338.13[医药卫生—基础医学]