We employed a highly sensitive combination method of retrograde tracing and immunohistochemistry to identify an alpha-melanocyte-stimulating hormone (alpha-MSH)-containing fiber pathway from zona incerta to cerebral cortex. Biotin-horseradish peroxidase injected into the parietal cortex of the rat labeled a number of neurons in the zona incerta bilaterally, and simultaneous staining with an alpha-MSH antiserum revealed that a part of these neurons are alpha-MSHergic.