[New development in glial cell research].

The term "neuroglia" indicates the glue for neurons. Because of the naming, electrophysiological inertness and misunderstanding of their real shape, the roles of those cells in the brain have been underestimated for a long time since their finding under the microscope. However, now we recognized those cells as active elements in the brain. Especially astrocytes can sense the activities of surrounding neurons through neurotransmitter receptors expressed on them, and they can integrate synaptic activities by releasing so called glio-transmitters, such as ATP, glutamate and D-serine. Recent studies have suggested the participation of important structure so called "tripartite synapse" built up among glial cells and neurons on the brain function. In this article dynamic feature of glial cells, especially astorocytes, will be demonstrated, and their possible roles in the brain functions and their disorders will be discussed. Since the brain science has been developed on neuron centric concepts until end of 20th century, the methods available for experimental researches are limited only for neuronal cells and structure. We need new concepts and new methods for studying the brain function based upon the complex and huge systems constructed by not only neurons but also glial cells as functional elements. Future studies on such systems will bring the final solution of brain functions and their disorder.