TY - JOUR
T1 - Expression of AMPA-glutamate receptor B subunit in rat hippocampal GABAergic neurons
AU - Racca, Claudia
AU - Catania, Maria Vincenza
AU - Monyer, Hannah
AU - Sakmann, Bert
PY - 1996
Y1 - 1996
N2 - The physiological properties of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptor (GluR) channels are determined by their subunit composition. In particular, the expression of the GluR-B subunit determines the divalent ion selectivity of the channel. We studied the distribution of GluR-B mRNA and protein in adult rat hippocampal GABAergic neurons combining non-radioactive in situ hybridization with immunocytochemistry. The majority of GABAergic hippocampal neurons were GluR-B mRNA-positive, but overall the levels of GluR-B transcript were lower than in pyramidal and granule cells, which showed the highest hybridization signal. The different GluR-B mRNA expression levels in GABAergic versus principal neurons were also observed at the protein level. There was a paucity of GluR-B/C immunoreactivity in the vast majority of somata of the GABAergic neurons studied, which contrasted with the strong expression of GluR-B/C proteins in the hippocampal principal neurons. Our results demonstrate the general low expression of the GluR-B subunit mRNA and GluR-B/C proteins in GABAergic hippocampal neurons. Considering the dominant role of the GIuR-B subunit in determining the divalent ion permeability of the receptor, it is likely that most GABAergic neurons express AMPA receptor channels with different calcium permeabilities.
AB - The physiological properties of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptor (GluR) channels are determined by their subunit composition. In particular, the expression of the GluR-B subunit determines the divalent ion selectivity of the channel. We studied the distribution of GluR-B mRNA and protein in adult rat hippocampal GABAergic neurons combining non-radioactive in situ hybridization with immunocytochemistry. The majority of GABAergic hippocampal neurons were GluR-B mRNA-positive, but overall the levels of GluR-B transcript were lower than in pyramidal and granule cells, which showed the highest hybridization signal. The different GluR-B mRNA expression levels in GABAergic versus principal neurons were also observed at the protein level. There was a paucity of GluR-B/C immunoreactivity in the vast majority of somata of the GABAergic neurons studied, which contrasted with the strong expression of GluR-B/C proteins in the hippocampal principal neurons. Our results demonstrate the general low expression of the GluR-B subunit mRNA and GluR-B/C proteins in GABAergic hippocampal neurons. Considering the dominant role of the GIuR-B subunit in determining the divalent ion permeability of the receptor, it is likely that most GABAergic neurons express AMPA receptor channels with different calcium permeabilities.
KW - cRNA probes
KW - Digoxigenin
KW - Glutamic acid decarboxylase
KW - Hippocampus
KW - Interneurons
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M3 - Article
C2 - 8921250
AN - SCOPUS:0029760440
VL - 8
SP - 1580
EP - 1590
JO - European Journal of Neuroscience
JF - European Journal of Neuroscience
SN - 0953-816X
IS - 8
ER -