Cerebellar excitatory and inhibitory amino acid receptors in multiple system atrophy.
We studied excitatory and inhibitory amino acid binding sites autoradiographically in control and multiple system atrophy (MSA) cerebella. Within the dentate nucleus (DN) of MSA specimens, we found a significant increase in the level of GABAA, benzodiazepine, and metabotropic binding sites compared with controls. In the granule cell layer, kainate, N-methyl-D-aspartate, and GABAA binding sites were all decreased significantly in MSA specimens compared with controls. In the molecular layer of MSA cerebellum, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate binding sites were decreased significantly compared with controls. Cerebellar cortical binding site decreases are likely due to Purkinje and granule cell loss. The increase of binding site levels in DN of MSA specimens may represent receptor up-regulation reflecting loss of descending inhibitory Purkinje cell and ascending excitatory afferents to the DN.
Department of Neurology, Massachusetts General Hospital, Boston 02114.
R H
RH
Price
R L
RL
Albin
S Y
SY
Sakurai
R J
RJ
Polinsky
J B
JB
Penney
A B
AB
Young
D000328:Adult; D000368:Aged; D001345:Autoradiography; D001480:Basal Ganglia Diseases / Q000378:metabolism* / Q000473:pathology; D002531:Cerebellum / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D009849:Olivopontocerebellar Atrophies / Q000378:metabolism* / Q000473:pathology; D011869:Radioligand Assay; D017459:Receptors, Amino Acid / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D012791:Shy-Drager Syndrome / Q000378:metabolism* / Q000473:pathology
D017459:Receptors, Amino Acid; D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate