A high GluR1 : GluR2 expression ratio is correlated with expression of Ca2+-binding proteins in rat forebrain neurons

Autor:	M, Kondo, S, Okabe, R, Sumino, H, Okado
Rok vydání:	2000
Předmět:	Neurons Calbindins Gene Expression Biological Transport Benzothiadiazines Calcium Channel Blockers Rats Rats Sprague-Dawley Parvalbumins Prosencephalon S100 Calcium Binding Protein G Calbindin 1 Quinoxalines Excitatory Amino Acid Agonists Animals Calcium RNA Messenger Receptors AMPA Excitatory Amino Acid Antagonists alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid Antihypertensive Agents Cells Cultured In Situ Hybridization
Zdroj:	The European journal of neuroscience. 12(8)
ISSN:	0953-816X
Popis:	alpha-Amino-3-hydroxy-5-methyl-4-isoxazle propionic acid (AMPA) receptors are ubiquitously expressed; however, their subtypes and abundance vary from region to region. We classified the neurons in various forebrain regions (hippocampus, striatum, amygdala, piriform cortex and somatosensory cortex) into six types: [R1+/R2+], [R1-/R2+], [R1+/R2-], [R1-/R2-], [R1++/R2+] and [R1++/R2-], and analysed the expression of Ca2+-binding proteins, such as parvalbumin and calbindin-D28k, using a triple-staining method. The neurons showing a high GluR1 : GluR2 expression ratio, [R1+/R2-], [R1++/R2+] and [R1++/R2-] neurons, comprised 13-30% of the total neuronal population. In addition, the expression of Ca2+-binding proteins was mainly observed in these three types of neurons. The results suggest that Ca2+-binding protein-positive neurons express Ca2+-permeable AMPA receptors, because the Ca2+-permeability of AMPA receptors is enhanced by the relative scarcity of the GluR2 subunit. To directly test the possibility that Ca2+-binding protein-positive neurons express Ca2+-permeable AMPA receptors, we performed Ca2+-imaging experiments in cultured cortical neurons. Ca2+ influx through AMPA receptors was measured selectively by addition of AMPA together with cyclothiazide in the presence of blockers of other Ca2+ influx routes. More than half of the calbindin-D28k-positive neurons showed a large increase in the intracellular Ca2+ concentration ([Ca2+]i), whilst most of the calbindin-D28k-undetectable neurons exhibited only a slight rise in [Ca2+]i after AMPA addition. These results suggest that the expression of calbindin-D28k is related to the expression of Ca2+-permeable AMPA receptors.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=pmid________::6b3ffce6ca6b516e1ec0730b5ec3057d https://pubmed.ncbi.nlm.nih.gov/10971623 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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