Immunohistochemical localization of GABAergic cells in the developing human dorsal lateral geniculate nucleus

GABAergic neurons were demonstrated in the dorsal lateral geniculate nucleus (dLGN) of human foetuses of 21 weeks gestation using unlabelled antibodies against gamma-aminobutyric acid (GABA). These inhibitory neurons are thus cytochemically identifiable prior to appearance of lamination, at a period when there is reportedly segregation of retinal afferents from both eyes and formation of morphologically defined synapses. Their presence in the prenatal period indicates that the morphological substrate responsible, in part, for the orientation sensitivity of the dLGN neurons exists before birth in man.