Elevated NMDA receptors in parkinsonian striatum.
Dopamine-glutamate interactions contribute to normal striatal function and have been implicated in neurotoxicity at nigrostriatal dopamine (DA) terminals. The present study examined the striata of idiopathic Parkinson's disease (PD) patients and age-matched controls for regional differences in the DA transporter and binding to N-methyl-D-aspartate (NMDA) receptors. [3H]Mazindol labeling of the DA transporter was reduced by 70-80% in the caudate and putamen of PD patients, with reductions being more extensive dorsally than ventrally. In contrast, L-[3H]glutamate binding to NDMA-sensitive receptors was 20-40% higher in PD cases than in controls. These findings raise the possibility that modifications occur within corticostriatal glutamate synapses of PD patients, possibly as a consequence of reduced nigrostriatal DA activity.
Weihmuller
F B
FB
Department of Psychobiology, University of California, Irvine 92717.
Ulas
J
J
Nguyen
L
L
Cotman
C W
CW
Marshall
J F
JF
D000368:Aged; D001345:Autoradiography; D002352:Carrier Proteins / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D008297:Male; D008454:Mazindol; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D010300:Parkinson Disease / Q000378:metabolism*; D017459:Receptors, Amino Acid / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017459:Receptors, Amino Acid; D016194:Receptors, N-Methyl-D-Aspartate; D008454:Mazindol