Edinger-Westphal nucleus: cells that project to spinal cord contain corticotropin-releasing factor

Combined retrograde transport and immunocytochemical methods were used to determine whether neurons in the Edinger-Westphal complex (EW) that project to the spinal cord also demonstrate corticotropin-releasing factor-like immunoreactivity (CRF-LI). Large injections of horseradish peroxidase (HRP) into cervical spinal cord retrogradely labeled cells throughout the extent of the EW complex. Most retrogradely labeled EW neurons also exhibited CRF-LI, evidence that EW is the origin of a direct CRF-containing pathway which links the rostral mesencephalon with spinal cord.