Increased perinuclear Ca2+ activity evoked by metabotropic glutamate receptor activation in rat hippocampal neurones.
AUTOR(ES)
Phenna, S
RESUMO
1. The effect of metabotropic glutamate receptor activation on intracellular Ca2+ activity (alpha Cai) of rat hippocampal pyramidal neurones in vitro was examined using ratiometric confocal laser scanning microscopy with the Ca(2+)-sensitive fluorescent probe indo-1 AM. 2. Metabotropic receptors were selectively activated with 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD; 100 microM) in the presence of D-2-amino 5-phosphonovaleric acid (D-APV), 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and CdCl2. Most pyramidal neurones (77/84) responded with an elevation in Ca2+ activity, maximal after 3-5 min. Fluorescence ratio responses were concentration dependent (EC50 approximately 10 microM) and were blocked by prior application of the antagonist (RS)-4-carboxy-3-hydroxyphenylglycine (RS-CHPG, 300 microM). 3. Responses to 1S,3R-ACPD (100 microM) also caused acidification of the neurones, from estimated control pH 7.2 to pH 6.6 (measured with the pH-sensitive dye SNAFL-calcein). The correction factor for indo-1 determination of Ca2+ was estimated to be x 1.4. 4. Elevations in alpha Cai were greater within the perinuclear region (> 1000 nM), than in the cytoplasm (approximately 200 nM). This region was devoid of staining by the endoplasmic reticulum staining dye 3,3'-dihexyloxacarbocyanine iodide (DiOC6(3)). 5. It is concluded that activation of metabotropic receptors in immature rat hippocampal pyramidal neurones leads to a large increase in perinuclear Ca2+ which would be well positioned to interact with the genome.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1156505Documentos Relacionados
- Fractional Ca2+ currents through somatic and dendritic glutamate receptor channels of rat hippocampal CA1 pyramidal neurones.
- Quisqualate-preferring metabotropic glutamate receptor activates Na(+)-Ca2+ exchange in rat basolateral amygdala neurones.
- Fast activation and inactivation of inositol trisphosphate-evoked Ca2+ release in rat cerebellar Purkinje neurones.
- GABAB receptor-mediated inhibition of Ca2+ currents and synaptic transmission in cultured rat hippocampal neurones.
- Ca2+ efflux mechanisms following depolarization evoked calcium transients in cultured rat sensory neurones.