Perea Gertrudis, Araque Alfonso
Instituto Cajal, Consejo Superior de Investigaciones Científicas, Doctor Arce 37, Madrid 28002, Spain.
J Physiol Paris. 2006 Mar-May;99(2-3):92-7. doi: 10.1016/j.jphysparis.2005.12.003. Epub 2006 Jan 25.
Glial cells were classically considered as supportive cells that do not contribute to information processing in the nervous system. However, considerable amount of evidence obtained by several groups during the last few years has demonstrated the existence of a bidirectional communication between astrocytes and neurons, which prompted a re-examination of the role of glial cells in the physiology of the nervous system. This review will discuss recent advances in the neuron-to-astrocyte communication, focusing on the recently reported properties of the synaptically evoked astrocyte Ca2+ signal that indicate that astrocytes show integrative properties for synaptic information processing. Indeed, we have recently shown that hippocampal astrocytes discriminate between the activity of different synapses, and respond selectively to different axon pathways. Furthermore, the astrocyte Ca2+ signal is modulated by the simultaneous activity of different synaptic inputs. This Ca2+ signal modulation depends on cellular intrinsic properties of the astrocytes, is bidirectionally regulated by the level of synaptic activity, and controls the spatial extension of the intracellular Ca2+ signal. Consequently, we propose that astrocytes can be considered as cellular elements involved in information processing by the nervous system.
神经胶质细胞传统上被认为是支持性细胞，不参与神经系统的信息处理。然而，在过去几年中，几个研究小组获得的大量证据表明，星形胶质细胞和神经元之间存在双向通信，这促使人们重新审视神经胶质细胞在神经系统生理学中的作用。本综述将讨论神经元与星形胶质细胞通信方面的最新进展，重点关注最近报道的突触诱发星形胶质细胞Ca2+信号的特性，这些特性表明星形胶质细胞在突触信息处理中具有整合特性。事实上，我们最近发现海马星形胶质细胞能够区分不同突触的活动，并对不同的轴突通路做出选择性反应。此外，星形胶质细胞Ca2+信号受到不同突触输入同时活动的调节。这种Ca2+信号调节取决于星形胶质细胞的细胞内在特性，受突触活动水平的双向调节，并控制细胞内Ca2+信号的空间扩展。因此，我们认为星形胶质细胞可被视为参与神经系统信息处理的细胞成分。
