Intercellular calcium signaling and gap junctional communication in astrocytes

✍ Scribed by Christian Giaume; Laurent Venance

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 602 KB
• Volume: 24
• Category: Article
• ISSN: 0894-1491
• DOI: 10.1002/(sici)1098-1136(199809)24:1<50::aid-glia6>3.0.co;2-4

✦ Synopsis

Two main characteristics of astrocytes are their elaborated intracellular calcium signaling and their high degree of intercellular communication mediated by gap junctional channels. In these cells a number of studies have contributed to demonstrate that the combination of these two properties provides a basis for a long-range signaling system within the brain. Intercellular calcium signaling, also termed calcium waves, allows astrocytes to communicate with each other and to interact with adjacent neurons. Most of the intra-and inter-cellular events involved in the initiation and propagation phases of this process has now been identified. This sequence of events includes the permeability of gap junction channels, which at the time-scale for calcium waves propagation, are likely permeated rather than closed by Ca 2ϩ and/or related signaling molecules like IP3. In addition, in some studies an external component have been reported to participate to the propagation process. Finally, the control of the spread of intercellular calcium signaling has been demonstrated to occur at several levels including phospholipase C, IP3 receptors, intracellular Ca 2ϩ stores, and cytoplasmic Ca 2ϩ buffering. Accordingly, normal and pathological situations that affect one or several of these steps can be predicted to influence on astrocytic calcium waves.