Functional morphology of excitable glial nets associated with sensory nerve endings-calcium image analysis.

与感觉神经末梢相关的可兴奋胶质网的功能形态-钙图像分析。

基本信息

批准号：
15590151
负责人：
IWANAGA Hiromi
金额：
$ 2.24万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

Recent studies have shown that glial cells respond to various stimuli by a transient elevation in the intracellular Ca^<2+> concentration, and that these signals mediate glial activities to regulate neuronal functions. In cutaneous sensory devices, glial elements connect with each other by branched processes to form a network extending among different axon terminals. In order to define spatiotemporal dynamics and physiological properties of the cell signals in these glial nets, calcium images of isolated lanceolate endings, motion receptors of rat vibrissae, were monitored by time-lapse confocal microscopy while the cells were stimulated by application of the neurotransmitter adenosine 5'-triphosphate (ATP), or by touching with a micromanipulator-driven glass needle. Morphological backgrounds of the glial signaling were observed electron microscopically. Stimulation with ATP evoked an oscillatory elevation in the intracellular Ca^<2+> concentration in the glial cells. Responses in thei … More r lamellar processes covering axon terminals always proceeded to those in their cell bodies. In each lamella, the initial wave evoked by a given trial of the stimulant arose from a specific locus within the cell process. Touching with a glass needle on lanceolates triggered a Ca^<2+> spike in the affected glial lamellae. The Ca^<2+> waves occasionally traveled within, and between the glial cells, to enter other glial processes enveloping neighboring lanceolates. These findings imply subcellular compartmentalization that may enable each glial lamella to modulate the activity of its accompanying lanceolate terminal through its own Ca signal as well as to regulate neighboring lanceolates through interlamellar signal propagation. Pharmacological experiments have shown that the ATP-evoked responses of the glia are mediated by the purinoceptor subtype P2Y_2, activation of which induces Ca^<2+> release from an intracellular store. Gliai lamellae of lanceolate endings examined by electron microscopy revealed smooth endoplasmic reticulum which would store Ca^<2+> in the lumen, and gap junctions which maybe involved in the intercellular signal propagation. Less

最近的研究表明，神经胶质细胞通过细胞内Ca^<2+>浓度的瞬时升高对各种刺激做出反应，并且这些信号介质具有培养基胶质活性以调节神经元功能。在皮肤感觉设备中，神经胶质元素通过分支过程相互连接，以形成在不同轴突终端之间延伸的网络。为了在这些神经胶质网中定义细胞信号的空间时间动力学和物理特性，通过延时共聚焦显微镜监测了分离的披针形末端的钙图像，大鼠颤动的运动受体，而通过将神经递质腺苷腺苷5'-triphathate（或通过触摸剂）刺激，而刺激细胞，而细胞是通过将神经递质腺苷的腺苷腺苷（神经递质腺苷）施加的。通过电子方式观察到神经胶质信号的形态学背景。用ATP刺激诱发了细胞内Ca^<2+>胶质细胞中的振荡升高。在……涵盖轴突终端的更多r层状过程中的响应总是向细胞体中的那些过程进行。在每个薄片中，由给定的刺激剂试验引起的初始波是由细胞过程中的特定基因座引起的。用玻璃针上的弹枪触摸触发了受影响的神经胶质薄片中的Ca^<2+>尖峰。 Ca^<2+>波偶尔会在内部和神经胶质细胞之间传播，以进入包裹着邻近兰西酸盐的其他神经胶质过程。这些发现暗示了亚细胞隔室化，这可能使每个神经胶质薄片通过其自身的CA信号以及通过层间信号传播调节其参与披针形末端的活性。药理学实验表明，胶质神经胶质的ATP诱发反应是由Purinoceptor亚型P2Y_2介导的，其激活诱导Ca^<2+>从细胞内存储中释放。通过电子显微镜检查的披针形末端的神经胶质层片显示出光滑的内质网，该网状网状会将Ca^<2+>存储在管腔中，并且可能参与细胞间信号传播的间隙连接。较少的