TYROSINE PHOSPHORYLATION OF NMDA RECEPTOR IN RAT STRIATUM - EFFECTS OF 6-OH-DOPAMINE LESIONS

N-METHYL-D-aspartate (NMDA) glutamate receptor properties are subject to a fine tuning by several regulatory mechanisms including phosphoryl ation of the receptor subunits. Here we show that two of these subunit s, NR2B and NR2A, are phosphorylated on tyrosine residues in vivo, in rat striatum, where NR2B is by far the most prominent tyrosine phospho rylated protein. Two weeks after unilateral lesioning of nigrostriatal dopaminergic neurones with 6-hydroxydopamine, tyrosine phosphorylatio n of NR2B was increased by similar to 20% in the ipsilateral striatum. The total amount of NR2B protein was unaltered. Thus, increased tyros ine phosphorylation of NR2B may account for some of the consequences o f dopamine deprivation on corticostriatal transmission and may play a role in some forms of synaptic plasticity.