Cooper M S
Department of Zoology, NJ-15, University of Washington, Seattle, WA 98195.
Biosystems. 1995;34(1-3):65-85. doi: 10.1016/0303-2647(94)01450-l.
Glial cells have recently been found to exhibit electrophysiological and metabolic responses to many neurotransmitters and neuromodulators. These findings have focused attention on the possibility that active signaling between neurons and glia could represent an important form of intercellular communication within the brain. Since glial and neuronal networks are both physically and metabolically interlinked, such intercellular signaling may represent a mechanism for inducing collective changes in the cellular physiology of neuronal and glial cell populations. Within the nervous tissue of both vertebrate and invertebrate organisms, glial cells are known to secrete extracellular signal molecules, modulate carbohydrate metabolism, and control the volume and ionic composition of extracellular space. In this paper, the roles that cytoplasmic [Ca2+] transients may play in regulating these glial cell functions are reviewed. Mechanisms by which intracellular Ca oscillations and intercellular Ca waves may be generated in neurotransmitter-stimulated glial cells are also discussed. In addition, it is proposed that rhythmic glial cell contractions and shape changes, which have been observed for many decades, are linked to Ca-induced secretion of ions, water, and neuroactive compounds. These activities represent mechanisms by which Ca-induced changes in glial cell physiology could potentially alter the excitability of neuronal networks.
最近发现神经胶质细胞对许多神经递质和神经调质表现出电生理和代谢反应。这些发现使人们将注意力集中在神经元与神经胶质细胞之间的主动信号传递可能代表大脑内一种重要的细胞间通讯形式这一可能性上。由于神经胶质细胞网络和神经元网络在物理和代谢上都是相互联系的，这种细胞间信号传递可能代表一种诱导神经元和神经胶质细胞群体细胞生理学发生集体变化的机制。在脊椎动物和无脊椎动物的神经组织中，已知神经胶质细胞会分泌细胞外信号分子、调节碳水化合物代谢，并控制细胞外空间的体积和离子组成。本文综述了细胞质[Ca2+]瞬变在调节这些神经胶质细胞功能中可能发挥的作用。还讨论了在神经递质刺激的神经胶质细胞中可能产生细胞内钙振荡和细胞间钙波的机制。此外，有人提出，几十年来观察到的神经胶质细胞有节奏的收缩和形状变化与钙诱导的离子、水和神经活性化合物的分泌有关。这些活动代表了钙诱导的神经胶质细胞生理学变化可能改变神经元网络兴奋性的机制。
