STRIATAL EXCITATORY AMINO-ACID RECEPTOR SUBUNIT EXPRESSION IN THE D-1A-DOPAMINE RECEPTOR-DEFICIENT MOUSE

The influence of dopamine receptor deletion on the expression and dist ribution of striatal excitatory amino acid (EAA) receptor subunits com prising the N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-me thyl-4-isoxazole propionic acid (AMPA) subtypes were examined in the D -1A dopamine (DA) receptor-deficient mouse. EAA receptor subunit immun ofluorescent staining was altered by the DA receptor genetic mutation. The NMDA-R-1 subunit was used as a marker for NMDA-type receptors, Th e number of striatal neurons expressing this subunit decreased and the re was a modest attenuation in the neuropil staining in the mutants in contrast to littermate controls. The R-1 subunit for the glutamate re ceptor (GluR(1)) was used as an indicator of the AMPA receptor subtype , Immunostaining for this subunit also showed changes induced by delet ion of the DA receptor subtype, In contrast to the NMDA-R-1 subunit, n europil staining for the GluR1 subunit was elevated in the mutant in c omparison to littermate controls, such that the immunofluorescent reac tion obscured detection of the subunit protein in striatal interneuron s. The results are discussed in relation to the potential impact on fu nctional interactions between the EAA and DA systems in the striatum.