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 phosphorylation of the receptor subunits. Here we show that two of these subunits, NR2B and NR2A, are phosphorylated on tyrosine residues in vivo, in rat striatum, where NR2B is by far the most prominent tyrosine phosphorylated protein. Two weeks after unilateral lesioning of nigrostriatal dopaminergic neurones with 6-hydroxydopamine, tyrosine phosphorylation of NR2B was increased by approximately 20% in the ipsilateral striatum. The total amount of NR2B protein was unaltered. Thus, increased tyrosine phosphorylation of NR2B may account for some of the consequences of dopamine deprivation on corticostriatal transmission and may play a role in some forms of synaptic plasticity.