Distribution of AMPA glutamate receptor GluR1 subunit-immunoreactive neurons and their co-localization with calcium-binding proteins and GABA in the mouse visual cortex.
The neuronal localization of alpha-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid (AMPA) glutamate receptor (GluR) subunits is vital as they play key roles in the regulation of calcium permeability. We have examined the distribution of the calcium permeable AMPA glutamate receptor subunit GluR1 in the mouse visual cortex immunocytochemically. We compared this distribution to that of the calcium-binding proteins calbindin D28K, calretinin, and parvalbumin, and of GABA. The highest density of GluR1-immunoreactive (IR) neurons was found in layers II/III. Enucleation appeared to have no effect on the distribution of GluR1-IR neurons. The labeled neurons varied in morphology; the majority were round or oval and no pyramidal cells were labeled by the antibody. Two-color immunofluorescence revealed that 26.27%, 10.65%, and 40.31% of the GluR1-IR cells also contained, respectively, calbindin D28K, calretinin, and parvalbumin. 20.74% of the GluR1-IR neurons also expressed GABA. These results indicate that many neurons that express calcium-permeable GluR1 also express calcium binding proteins. They also demonstrate that one fifth of the GluR1-IR neurons in the mouse visual cortex are GABAergic interneurons.
Kim
Tae-Jin
TJ
Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, Korea.
Ye
Eun-Ah
EA
Jeon
Chang-Jin
CJ
D000818:Animals; D064092:Calbindin 1; D064032:Calbindin 2; D064026:Calbindins; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D010320:Parvalbumins / Q000378:metabolism; D010640:Phenothiazines / Q000378:metabolism; D021381:Protein Transport; D018091:Receptors, AMPA / Q000276:immunology* / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D014793:Visual Cortex / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D064092:Calbindin 1; D064032:Calbindin 2; D064026:Calbindins; D002135:Calcium-Binding Proteins; D010320:Parvalbumins; D010640:Phenothiazines; D018091:Receptors, AMPA; D064030:S100 Calcium Binding Protein G; D005680:gamma-Aminobutyric Acid; C576499:Calb1 protein, mouse; C576511:Calb2 protein, mouse; C009469:thionine