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Metabotropic glutamate receptor 5 (mGluR5)‐mediated phosphoinositide hydrolysis and NMDA‐potentiating effects are blunted in the striatum of aged rats: a possible additional mechanism in striatal senescence
Author(s) -
Domenici Maria Rosaria,
Pintor Annita,
Potenza Rosa Luisa,
Gaudi Simona,
Grò Maria Cristina,
Passarelli Francesca,
Reggio Rosaria,
Galluzzo Mariangela,
Massotti Marino,
Popoli Patrizia
Publication year - 2003
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.2003.02649.x
Subject(s) - metabotropic glutamate receptor 5 , metabotropic glutamate receptor , metabotropic glutamate receptor 1 , striatum , nmda receptor , glutamate receptor , neuroscience , chemistry , metabotropic glutamate receptor 6 , pharmacology , metabotropic glutamate receptor 7 , metabotropic glutamate receptor 4 , senescence , mechanism (biology) , metabotropic receptor , receptor , biology , microbiology and biotechnology , biochemistry , dopamine , philosophy , epistemology
The aim of the present work was to verify whether an impairment of subtype 5 metabotropic glutamate receptor‐mediated neurotransmission did occur in the aged striatum. To this end, the ability of the subtype 5 metabotropic glutamate receptor agonist, RS‐2‐chloro‐5‐hydroxyphenylglycine, to stimulate phosphoinositide hydrolysis and to potentiate N ‐methyl‐ d ‐aspartate‐induced effects in striatal slices from young (3 months) and aged (24 months) rats was compared. The ability of RS‐2‐chloro‐5‐hydroxyphenylglycine to induce maximal phosphoinositide turnover and to potentiate N ‐methyl‐ d ‐aspartate effects was significantly reduced in slices from old vs. young rats. These changes were associated with a significant reduction in the expression of subtype 5 metabotropic glutamate receptor protein (−28.8%) and phospholipase C‐β1 (−55.8%) in old striata, while receptor messenger ribonucleic acid expression was unchanged. These results show that the signalling associated with subtype 5 metabotropic glutamate receptors undergoes significant age‐related changes and that a reduced expression of subtype 5 metabotropic glutamate receptors and, more importantly, phospholipase C‐β1 may account for the functional decline of subtype 5 metabotropic glutamate receptors.