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.