UROCORTIN-LIKE IMMUNOREACTIVITY IN THE SUBSTANTIA-NIGRA, VENTRAL TEGMENTAL AREA AND EDINGER-WESTPHAL NUCLEUS OF RAT

Neurons showing intense urocortin-like immunoreactivity (Ucn-IR) were found immunohistochemically in the substantia nigra pars compacta (SNc ) and ventral tegmental area (VTA), as well as in Edinger-Westphal nuc leus (E-W), in the rat brain. Almost all Ucn-immunoreactive neuronal c ell bodies in the SNc and VTA showed immunoreactivity for tyrosine hyd roxylase. Injection of a retrograde tracer, colloidal gold-labeled WGA apoHRP, into the cervical spinal cord resulted in labeling of some E-W neurons with Ucn-IR. These findings suggest that Ucn is located in th e cell bodies of dopaminergic neurons, as well as in the cell bodies o f E-W neurons sending axons to the spinal cord. (C) 1998 Elsevier Scie nce Ireland Ltd.