Metabotropic glutamate receptors mGluR1 alpha and mGluR2/3 display dynamicexpression patterns in developing rat striatum

The developmental expression of two metabotropic glutamate receptors (mGluR ), mGluR1 alpha and mGluR2/3 was evaluated in the rat striatum from birth t o adulthood. The mGluR1 alpha receptor subtype displayed a patchy organizat ion perinatally that became more homogeneous after the first postnatal week . The adult pattern of receptor expression consisted of homogeneous punctat e profiles spread throughout the striatum. The mGluR2/3 receptor subtype ex hibited a unique pattern of ontogenic expression, being associated exclusiv ely with fibers of the internal capsule that penetrate the striatum, during the perinatal period. The protein localization for this subtype spread int o the striatal neuropil after the first postnatal week, in parallel to the development of afferent terminations and arborizations to the nucleus. Unli ke the ionotropic GluR subunits that are associated with somata and dendrit es, neither subtype of metabotropic receptor was associated with neuronal c ell bodies within the striatum. Copyright (C) 2001 S. Karger AG, Basel.