Increasing proportions of tyrosine hydroxylase-immunoreactive interneurons colocalize with choline acetyltransferase or vasoactive intestinal peptide in the developing rat cerebral cortex

►Subsets of TH-immunoreactive neurons coexpressed ChAT or VIP in the rat neocortex. ►Proportions of TH/ChAT- and TH/VIP-colabeled cells increased postnatally. ►Many TH somata were apposed to cortical microvessels labeled with aquaporin-4. ►Many TH cells associated with microvessel were colabeled with ChAT or VIP. ►Cortical TH neurons did not coproduce nitric oxide synthase.