Ontogeny of 3H-muscimol binding to membranes of chick forebrain.

A potent GABA agonist, 3H-muscimol, was used to investigate the development of GABA receptors in left and right hemispheres of chick forebrain from day 12 in ovo to day 21 post-hatch. Total specific 3H-muscimol binding (p mol mg-1 protein) increases rapidly in ovo, reaching a peak at around day one post-hatch and then showing a slow decline to approximately 50% of the maximal level at day 21 post-hatch. Despite the considerable evidence from previous studies of lateralization of avian brain function, no significant hemispheric differences were found in 3H-muscimol binding (either of p mol hemisphere-1 or p mol mg protein-1) at any of the developmental ages examined.