去甲肾上腺素调制大鼠体感皮层神经元电活动的受体机制Ⅰ.α-肾上腺素能受体的作用  

RECEPTOR MECHANISM OF NORADRENALINE MODULATING THE ELECTRICAL ACTIVITY OF NEURONS IN THE PRIMARY SOMATOSENSORY CORTEX OF RATSⅠ. EFFECT OF α ADRENORECEPTOR

作　　者：胡必利[1] 韩伟[2] 

机构地区：[1]南华大学基础医学院生理学教研室,衡阳421001 [2]怀化医学高等专科学校生理学教研室,怀化418000

出　　处：《中国现代医学杂志》2002年第7期6-9,12,共5页China Journal of Modern Medicine

摘　　要：目的 :探讨α-肾上腺素能受体在去甲肾上腺素 (NA)调制大鼠体感皮层神经元的诱发和自发放电活动中的作用。方法 :用SD大鼠、多管玻璃微电极刺激和记录、微电泳注射 ,以及对诱发单位放电 (SI-SEUD)过程作标准化互协方差函数 (NCCVF)处理 ,对自发放电过程作平均放电率 (MFR)处理 ,观察微电泳去甲肾上腺素、α -肾上腺素能受体拮抗剂酚妥拉明和育亨宾前后放电过程的变化。结果 :当小剂量 (2 0nA)NA使SI -SEUD的积分值减少 (P <0 .0 0 1) ,对其产生抑制效应 ,微电泳α -肾上腺素能受体拮抗剂酚妥拉明和育亨宾都能阻断这种效应 ,使NCCVF积分值恢复到微电泳前的对照水平 ;当大剂量 (80nA)NA使SI -SEUD的积分值加大 (P <0 .0 0 1) ,对其产生易化效应时 ,微电泳酚妥拉明能部分阻断该种易化作用 (与微电泳NA比较 ,P<0 .0 1) ,使SI -SEUD积分值朝向微电泳前的对照水平变化 (与对照实验比较 ,P <0 .0 5 ) ;而微电泳α2 -肾上腺素能受体拮抗剂育亨宾无此作用 ;③当中等剂量 (5 5nA)NA使体感皮层神经元自发放电的MFR明显升高 (P <0 .0 0 1) ,对其产生兴奋效应时 ,微电泳α2 -肾上腺素能受体拮抗剂育亨宾能阻断这种兴奋效应 ,使其MFR降低到对照水平。结论 :去甲肾上腺素对体感皮层Ⅰ区神经元的抑制诱发放电和易化自发?Objective:To reseach into the α-adrenoreceptor mechanism of noradrenaline (NA) modulating the neuronal discharges,evoked and spontaneous,in the primary somatosensory cortex of rats.Methods:The experiments were investigated in the Sprague-Dawley (SD) rats anesthetized with urethane.The signals of the discharges of neurons in primay somatosensory cortex recorded by multi-barrelled glass microelectrode were statistically processed by the microcomputer with the normalized cross-covarioance functions (NCCVF),for the unit discharges of neurons in primary somatosensory cortex (SI area) evoked by stimulationg saphenous nerve (SI-SEUD),and the mean firing rate (MFR),for the spontaneous activity.The changes of spontaneous activity in MFR and SI-SEUD in NCCVF were comparatively analysed before,during and after microiontophoretic application of NA,and phentolamine and yohimbine that were α-adrenergic receptor antagonist.Results:①The integrative values of SI-SEUD in NCCVF decreased obviously (compared with control, P <0.001) during microiontophoresis NA with small dosage of 20nA.It resulted from the inhibitory effect of NA of SI-SEUD.The integrative values of SI-SEUD in NCCVF could not decreased (compared with control, P >0.05) during microiontophoresis NA the same with phentolamine,or yohimbine.It indicates that the inhibitory effect of NA on SI-SEUD could be blocked by phentolamine and yohimbine.②The integrative values of SI-SEUD in NCCVF increased obviously (compared with control, P <0.001) because of microiontophoresis NA with large dosage of 80nA.It resulted from the facilitatory effect of NA on SI-SEUD.The integrative values of SI-SEUD in NCCVF could not increase (compared with control, P> 0.05) during microiontophoresis NA the same with phentolamine.But that increased during microiontophoresis NA the same with yohimbine.It indicates that the facilitatory effect of NA of SI-SEUD could be blocked by phentolamin and not by yohimbine.③MFR of neurons in the primary somatosensory cortex (SI area)increased o

关 键 词：去甲肾上腺素 体感皮层Ⅰ区 Α受体 受体拮抗剂 酚妥拉明 育亨宾 调制神经元活动 

分 类 号：R338[医药卫生—人体生理学]