The effect of intraperitoneal injection of GABA or GHBA on monoamine histofluorescence in the rat brain.

Using the Falck-Hillarp histofluorescence method we studied the effect of gamma-aminobutyric acid (GABA) or gamma-hydroxybutyric acid (GHBA) on catecholaminergic (CA) and serotoninergic (5-HT) neurons in the rat brain. Both GABA as well as GHBA enhanced the CA fluorescence in noradrenergic (NA) terminals in the cerebellar cortex, which suggested that the NA content increased in these terminals. GHBA but not GABA also enhanced the fluorescence in dopaminergic (DA) terminals in the neostriatum and limbic structures. No significant changes of fluorescence were found in 5-HT neurons after both compounds. The results obtained suggest that, apart from the known GABA-DA interaction, there exists also a GABA-NA interaction in the cerebellar cortex.