SELECTIVE DISTRIBUTION PATTERN OF GAMMA-HYDROXYBUTYRATE RECEPTORS IN THE RAT FOREBRAIN AND MIDBRAIN AS REVEALED BY QUANTITATIVE AUTORADIOGRAPHY

Using quantitative autoradiography to study the precise distribution of gamma-hydroxybutyrate high-affinity binding sites, the present results showed the heterogeneous localization of these sites in cortical and hippocampal layers and also in some diencephalic and mesencephalic nuclei. In frontal, parietal and temporal cortex, GHB binding sites are generally distributed in three distincts layers. The olfactory system, the amygdala, septum, basal ganglia and substantia nigra also exhibited significant amounts of GHB receptors. In thalamus, the radioactivity was heterogeneously distributed, the highest amounts being in the lateral posterior nucleus. Hypothalamus, cerebellum, colliculi and pons-medulla were apparently devoid of binding sites. This more accurate mapping of GHB high-affinity receptors in rat brain is due to some technical improvements and the use of [H-3]GHB of higher specific activity.