Immunohistochemical analysis of the localization of guanine nucleotide-binding protein in the mouse brain.

A guanine nucleotide-binding protein, G0, is a heterotrimer with the alpha- and beta gamma-subunits (referred to here as alpha 0 and beta gamma, respectively). We examined the distribution pattern of the anti-alpha 0 and anti-beta gamma immunoreactive products in the hippocampus, and cerebral and cerebellar cortices of the mouse brain. In the hippocampus, alpha 0- and beta gamma-immunoreactivities were localized in the neuropil of the stratum oriens, stratum radiatum and stratum lacunosum-moleculare, but were absent from the cell bodies of the pyramidal cells and their apical dendritic shafts. In the cerebral cortex, alpha 0- and beta gamma-immunoreactivities were seen in the neuropil of all 6 layers of the cerebral cortex, especially in the uppermost molecular layer (layer I), and were absent from cell bodies of neurons and their apical dendritic shafts. In the cerebellar cortex, the molecular layer was heavily stained with anti-alpha 0 and beta gamma-antibodies. The present study revealed that the distribution pattern of beta gamma-immunoreactivities in these structures of the mouse brain was strikingly similar to that of the alpha 0-immunoreactivities.