HISTOCHEMICAL CHARACTERIZATION OF THE PRETECTO-GENICULATE PROJECTION IN KITTEN AND ADULT CAT

Neurons in the pretectal nuclear complex projecting to the dorsal late ral geniculate nucleus (LGNd) in cat were studied at different postnat al ages by using a combination of retrograde tracing techniques with g lutamic acid decarboxylase (GAD) in situ hybridisation and calbindin-D -28k (CALB) and parvalbumin (PARV) immunocytochemistry. About 50% of t he neurons retrogradely labelled from the LGNd expressed GAD mRNA and this percentage did not change during postnatal development. LGNd-proj ecting neurons were never observed to be CALB- or PARV-immunoreactive.