Regional distribution of high-affinity gamma-[3H]hydroxybutyrate binding sites as determined by quantitative autoradiography.
The distribution of high-affinity binding sites for gamma-[3H]hydroxybutyrate in coronal sections of rat brain was studied by quantitative autoradiographic techniques. Binding sites for this naturally occurring substance, which may possibly have a neurotransmitter role, are concentrated in some restricted areas of the brain, particularly in the limbic system. The hippocampus (especially field CA1 of Ammon's horn, at 292 fmol/mg of tissue), septum (72 fmol/mg of tissue), and cortex (frontal, 113 fmol/mg of tissue; parietal, 103 fmol/mg of tissue; cingulate, 114 fmol/mg of tissue; and entorhinal, 134 fmol/mg of tissue) show pronounced labeling with gamma-[3H]hydroxybutyrate. Binding is much lower in caudatus-putamen (50 fmol/mg of tissue), thalamus, and hypothalamus. Caudal parts of the brain (cerebellum, pons, and medulla) are practically devoid of binding sites. These results strongly support a functional role of endogenous gamma-hydroxybutyrate in particularly restricted areas of the rat brain.
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism; D006885:Hydroxybutyrates / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface; D011963:Receptors, GABA-A / Q000378:metabolism*; D012688:Septum Pellucidum / Q000378:metabolism; D012978:Sodium Oxybate / Q000378:metabolism*; D014018:Tissue Distribution
C039403:4-hydroxybutyric acid receptor; D006885:Hydroxybutyrates; D011956:Receptors, Cell Surface; D011963:Receptors, GABA-A; D012978:Sodium Oxybate