VOLATILE ANESTHETICS AND NEURONAL CALCIUM

神经元将电刺激和化学刺激转化为 通过Ca 2+易位获得生理学上有意义的信息， 再分配研究人员将在拟议的 研究表明，挥发性麻醉剂（VA），氟烷和异氟烷， 干扰正常细胞外和细胞内Ca 2+转运， VA对Ca ~（2+）稳态的影响（易位和 再分配）取决于刺激的类型。研究将在 人神经母细胞瘤细胞系SH-SY 5 Y细胞具有许多特征， 肾上腺素能神经元，在大鼠海马神经元的原代培养， 用N型Ca 2+通道的α和β亚基转染的HEK 293细胞。 使用细胞内Ca 2+荧光，单通道和全细胞 膜片钳，去甲肾上腺素（NA）分泌的放射性同位素测量，以及 分子生物学技术来产生N型Ca 2+通道，我们将 实现以下具体目标：（1）确定调解机制 VA诱导的K+-诱发的[Ca 2 +]cyt瞬变增加，并确定是否 VA还增强由电刺激引起的[Ca 2 +]cyt瞬变; 2） 确定导致VA诱导的抑郁症的机制， 卡巴胆碱诱发的[Ca 2 +]cyt;短暂的; 3）研究Ca 2+的来源， 调节VA对神经元L-型Ca ~（2+）通道的作用; 4）研究VA对神经元L-型Ca ~（2+）通道的影响。 对N型Ca 2+通道的作用，以及G蛋白的参与;以及5） 研究哪些Ca 2+来源对于介导NA释放是重要的， VA暴露是否改变[Ca 2 +]cyt和NA释放之间的关系， 并确定VA对NA释放的作用是否依赖于暴露 时间到了。这些调查的结果将有助于确定， Ca 2+稳态的改变是Vas的基本作用， 它们与麻醉过程直接相关。这项研究将导致 鉴定VA靶向的细胞器和分子， 将有助于未来开发更特异性的麻醉药物。

Neurons translate electrical and chemical stimuli into physiologically meaningful information by Ca2+ translocation and redistribution. The hypothesis the investigators will test in the proposed studies is that the volatile anesthetics (VA), halothane and isoflurane, interfere with normal extra- and intracellular Ca2+ translocation and distribution, and that the VA effect on Ca2+ homeostasis (translocation and redistribution) depends on the type of stimuli. Studies will be performed in a human neuroblastoma cell line, SH-SY5Y cells, that has many characteristics of adrenergic neurons, in rat hippocampal neurons in primary culture, and in HEK293 cells transfected with alpha and beta subunits of N-type Ca2+ channels. Using intracellular Ca2+ fluorescence, single channel and whole cell patch-clamp, radioisotopic measurement of noradrenaline (NA) secretion, and molecular biologic techniques to generate N-type Ca2+ channels, we will accomplish the following specific aims: 1) identify the mechanisms mediating the VA-induced increase in the K+-evoked [Ca2+]cyt transient and determine if VA also enhance [Ca2+]cyt transients resulting from electrical stimulation; 2) identify the mechanisms that lead to the VA-induced depression of the Carbachol-evoked [Ca2+]cyt; transient; 3) investigate the source of Ca2+ that modulates the VA action on neuronal L-type Ca2+ channels; 4) investigate the VA action on N-type Ca2+ channels, and the involvement of G-proteins; and 5) investigate which sources of Ca2+ are important for mediating NA release, whether VA exposure alters the relationship between [Ca2+]cyt and NA release, and determine whether the VA action on NA release is dependent on the exposure time to Vas. The results of these investigations will help to establish that modifications of Ca2+ homeostasis are a fundamental effect of the Vas and that they are directly related to the process of anesthesia. This study will lead to the identification of organelles and molecules that are targets of VA's that will assist in the future development of more specific anesthetic drugs.