Expression of group I metabotropic glutamate receptors in rat hippocampal cells in culture and their characterization by intracellular calcium ion dynamics.
The distribution of group I metabotropic glutamate receptors in rat hippocampal cells in culture was examined by calcium imaging and immunocytochemistry. To distinguish different cell types in the culture, the effects of t-ACPD ((1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid) and of NMDA (N-methyl-D-aspartate) were examined. About 40% of the cultured cells showed either a transient increase or a sustained or oscillatory increase in the intracellular calcium concentration ([Ca(2+)](i)) during t-ACPD administration, while about 60% of the cells showed a sustained [Ca(2+)](i) increase in response to NMDA. Cells that showed an oscillatory [Ca(2+)](i) change during t-ACPD administration did not respond to NMDA administration, while cells that showed a sustained [Ca(2+)](i) increase during NMDA administration did not show any oscillatory response to t-ACPD. After pharmacological examination using those two agonists, the cultured cells were subjected to immunocytochemistry using anti-GFAP and ant-MAP-2 antibodies to distinguish, respectively, astrocytes and neurons. All cells responding to NMDA with a sustained [Ca(2+)](i) increase were MAP-2-positive, whereas all cells showing either oscillatory or sustained [Ca(2+)](i) increase in response to t-ACPD were GFAP-positive. The present results show that, in these cultures, group I metabotropic glutamate receptors are mainly expressed on glial cells and contribute to dynamic [Ca(2+)](i) changes in astrocytes.
Yoshida
Yoshitoku
Y
Laboratory of Cellular Neurobiology, School of Life Science, Tokyo University of Pharmacy and Life Science, Tokyo, Japan.
Matsumoto
Nagisa
N
Tsuchiya
Remi
R
Morita
Mitsuhiro
M
Miyakawa
Hiroyoshi
H
Kudo
Yoshihisa
Y
D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism*; D016202:N-Methylaspartate / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000096:biosynthesis*
D002118:Calcium; D003515:Cycloleucine; D016202:N-Methylaspartate; D018091:Receptors, AMPA; C036361:1-amino-1,3-dicarboxycyclopentane