Extension of glial processes by activation of Ca2+-permeable AMPA receptor channels

• Published in: Neuroreport Vol. 12; no. 4; p. 745
• Main Authors: Ishiuchi, S, Tsuzuki, K, Yamada, N, Okado, H, Miwa, A, Kuromi, H, Yokoo, H, Nakazato, Y, Sasaki, T, Ozawa, S
• Format: Journal Article
• Language: English
• Published: England 26.03.2001
• Subjects: Adenoviridae - genetics; Animals; Calcium - metabolism; Cell Size - drug effects; Cell Size - physiology; Cells, Cultured; Cerebellum - cytology; Excitatory Amino Acid Antagonists - pharmacology; Gene Expression - physiology; Glutamic Acid - pharmacology; Neuroglia - cytology; Neuroglia - drug effects; Neuroglia - metabolism; Quinoxalines - pharmacology; Rats; Rats, Wistar; Receptors, AMPA - antagonists & inhibitors; Receptors, AMPA - genetics; Receptors, AMPA - metabolism
• ISSN: 0959-4965
• DOI: 10.1097/00001756-200103260-00026

AMPA type-glutamate receptor channels (AMPARs) assembled without the GluR2 (GluR-B) subunit are characterized by high Ca2+ permeability, and are expressed abundantly in cerebellar Bergmann glial cells. Here we show that the morphology of cultured Bergmann glia-like fusiform cells derived from the rat cerebellum was changed by manipulating expression of Ca2+-permeable AMPARs using adenoviral vector-mediated gene transfer. Converting endogenous Ca2+-permeable AMPARs into Ca2+-impermeable channels by viral-mediated transfer of GluR2 gene induced retraction of glial processes. In contrast, overexpression of Ca2+-permeable AMPARs markedly elongated glial processes. The process extension was blocked by 2,3-Dihydroxy-6-nitro-7-sulfamoylbenzo(F)quinoxaline (NBQX), a specific antagonist of AMPAR. These results indicate that glutamate regulates the morphology of glial processes by activating Ca2+-permeable AMPARs.