The occurrence of gamma-aminobutyric acid (GABA)-containing cells in cultures of retinas from the human fetus.

gamma-Aminobutyric acid (GABA) immunoreactivity is demonstrated by the indirect immunofluorescence technique in a small population of retinal neurons cultured from human fetuses. Positive staining was restricted to a few cells and could be observed as soon as the cells became attached to the substrate (within 5 hr). It is therefore concluded that the GABA-positive cells are determined prenatally. The GABA-positive cells grow processes during development in culture and remain constant in numbers. These cells have a different morphology from either GFAP-positive cells or serotonin-accumulating cells. It is suggested that the GABA-positive cells in culture are probably amacrine neurones. Cultures of human retinal dissociates may therefore provide an alternative means of studying specific cell types should a constant supply of living human retinas be difficult to obtain.