Temporal development of GABA agonist induced alterations in ultrastructure and GABA receptor expression in cultured cerebellar granule cells.
The temporal development of the effect of THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) on the ultrastructure composition and GABA receptor expression in cerebellar granule cells was investigated by quantitative electron microscopy (morphometric analysis) and GABA binding assays. It was found that the cytoplasmic density of smooth endoplasmic reticulum was decreased, while the cytoplasmic density of rough endoplasmic reticulum, Golgi apparatus, vesicles and coated vesicles was greatly enhanced after exposure of the cells to THIP (150 microM) for only 1 hr. In cerebellar granule cells exposed to THIP (150 microM) for 3 hr low affinity GABA receptors were induced. These findings show that the effect of THIP on the ultrastructure composition and GABA receptor expression in cultured cerebellar granule cells may be interrelated and moreover it is likely that the turn-over of GABA receptors is extremely fast.
Hansen
G H
GH
Department of Biochemistry A, University of Copenhagen, Denmark.
Belhage
B
B
Schousboe
A
A
Meier
E
E
D000818:Animals; D002478:Cells, Cultured; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D007555:Isoxazoles / Q000494:pharmacology*; D007700:Kinetics; D008854:Microscopy, Electron; D015388:Organelles / Q000187:drug effects / Q000648:ultrastructure; D010080:Oxazoles / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D007555:Isoxazoles; D010080:Oxazoles; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid; C015542:gaboxadol