Antiserum Raised against Residues 159-168 of the Guanine Nucleotide-Binding Protein Gi3-α Reacts with Ependymal Cells and Some Neurons in the Rat Brain Containing Cholecystokinin- or Cholecystokinin- and Tyrosine 3-hydroxylase-Like Immunoreactivities
Abstract
Antibodies raised against a synthetic deca-peptide corresponding to a specific sequence of Gi3-alpha protein (an inhibitory guanine nucleotide-binding protein) were used to analyze Gi3-alpha-like immunoreactivity in brain sections from colchicine-treated rats by indirect immunofluorescence histochemistry. Gi3-alpha-peptide-positive cell bodies were found in the ventral tegmental area and substantia nigra, and these cells were also cholecystokinin (CCK)- and tyrosine 3-hydroxylase-positive. Gi3-alpha-peptide staining was observed in perikarya in the hippocampus and in fibers in the nucleus accumbens, tuberculum olfactorium, bed nucleus of stria terminalis, and a spino-thalamic tract, where it coexisted with CCK-like immunoreactivity as well. No coexistence with CCK occurred in Gi3-alpha-peptide-positive ependymal cells outlining the aqueduct and ventricles. Preadsorption of Gi3-alpha antibodies with CCK-8 or CCK-33 did not alter Gi3-alpha-peptide staining. The occurrence of Gi3-alpha-peptide-like immunoreactivity in CCK-containing neurons may indicate the presence of Gi3-alpha protein and in CCK/dopamine neurons may indicate an association of this Gi protein with dopamine autoreceptors.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- December 1988
- DOI:
- 10.1073/pnas.85.23.9351
- Bibcode:
- 1988PNAS...85.9351C