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醫(yī)學(xué)論文范文:視前區(qū)下丘腦前部溫敏神經(jīng)元電生理特性的離子通道機(jī)制
【摘要】 視前區(qū)下丘腦前部(POAH)是機(jī)體最重要的體溫調(diào)節(jié)中樞。POAH的溫度敏感神經(jīng)元,通過整合中樞及外周的溫度變化信息,以及調(diào)節(jié)效應(yīng)神經(jīng)元的活動(dòng)而在POAH的體溫調(diào)節(jié)作用中扮演重要角色。研究POAH神經(jīng)元電生理特性,特別是溫度敏感性的機(jī)制,對(duì)于揭示POAH神經(jīng)元的體溫調(diào)節(jié)作用具有重要意義。本文就POAH神經(jīng)元電生理特性及溫度敏感性的離子通道機(jī)制研究進(jìn)展作一綜述。
【關(guān)鍵詞】 視前區(qū)下丘腦前部;溫度敏感神經(jīng)元;電生理;離子通道
Ion channel mechanisms of electrophysiological properties in preoptic anterior hypothalamus temperaturesensitive neurons
WANG Nian,TANG Yu,SHEN Ziling
(Department of Physiology,Chengdu Medical College,Chengdu 610083,China)
【Abstract】 The preoptic anterior hypothalamus(POAH)is a principal center for body temperature regulation.Thermoregulatory neurons found in the POAH play critical roles in thermoregulation through integrating afferent and central thermal information,and controlling the physiological behavior of effector neurons.It is of great importance to ascertain the mechanisms of neurons electrophysiological properties,especially thermosensitivity for understanding the thermoregulation action of POAH neurons.This review summarized the progress in the study on the ion channel mechanisms of electrophysiological properties in POAH temperaturesensitive neurons.
【Key words】 preoptic anterior hypothalamus;temperaturesensitive neurons;electrophysiology;ion channel
視前區(qū)下丘腦前部(POAH)在體溫調(diào)節(jié)的中樞整合中具有重要作用,對(duì)體內(nèi)外溫度的改變有生理性和行為性的雙重調(diào)節(jié)反應(yīng)[1]。當(dāng)POAH區(qū)和外界溫度升高時(shí),動(dòng)物會(huì)出現(xiàn)散熱反應(yīng),如皮膚血管舒張、出汗、喘息等;當(dāng)POAH區(qū)和外界溫度下降時(shí),動(dòng)物則出現(xiàn)熱保留以及產(chǎn)熱反應(yīng),如皮膚血管收縮、棕色脂肪組織產(chǎn)熱、戰(zhàn)栗等。電生理研究對(duì)POAH的溫度調(diào)節(jié)反應(yīng)作出了解釋,即在POAH存在著可以感受自身溫度與外周溫度變化的溫度敏感神經(jīng)元,它們?cè)诟惺軠囟茸兓?通過調(diào)節(jié)溫度效應(yīng)神經(jīng)元的活動(dòng)實(shí)現(xiàn)散熱或產(chǎn)熱的調(diào)節(jié)反應(yīng)。多年來學(xué)者一直在致力于研究POAH溫度敏感神經(jīng)元的電生理特性及其離子通道機(jī)制,本文對(duì)這方面的研究進(jìn)展作一綜述醫(yī).學(xué).全.在.線gydjdsj.org.cn。
1 POAH神經(jīng)元分類
在POAH區(qū)分布著具有自發(fā)放電特性的神經(jīng)元和刺激后才產(chǎn)生放電的靜息神經(jīng)元。根據(jù)神經(jīng)元的放電頻率與溫度變化的關(guān)系,可以進(jìn)一步把自發(fā)放電神經(jīng)元群細(xì)分為3類。其中約20%的神經(jīng)元放電頻率隨溫度上升而增加,其熱系數(shù)≥0.8 imp /S.℃,稱為熱敏神經(jīng)元;約少于5%的神經(jīng)元放電頻率隨溫度下降而增加,其熱系數(shù)≤0.6 imp /S.℃,稱為冷敏神經(jīng)元;剩下約70%的自發(fā)放電神經(jīng)元群放電頻率不受溫度改變的影響,稱為溫度不敏感類型。
