Dopamine transporter expression distinguishes dopaminergic neurons from other catecholaminergic neurons in the developing zebrafish embryo

To characterize the formation of the dopaminergic system in the developing zebrafish CNS, we cloned cDNAs encoding tyrosine hydroxylase (th), an enzym e in dopamine synthesis, and the dopamine transporter (dat). a membrane tra nsport protein which terminates dopamine action by re-uptake, Dopaminergic neurons are first detected between IS and 19 h post-fertilization in a clus ter of cells in the ventral diencephalon. Subsequently, th and dat detectio n identifies dopaminergic neurons in the olfactory bulb, the pretectum. the retina and the locus coeruleus. Neurons expressing rh but not dat are adre nergic or noradrenergic, and are found in the locus coeruleus, the medulla. the likely analog of the carotid body, and precursors of the enteric and s ympathetic nervous system. (C) 2001 Elsevier Science Ireland Ltd. All right s reserved.