Evidence that urocortin is absent from neurons of the Edinger-Westphal nucleus in pigeons. J.A. Cavani, A. Reiner, S.L. Cuthbertson, J.C. Bittencourt and C.A.B. Toledo. Brazilian Journal of Medical and Biological Research, 36 (12): 1695, 2003.

Figure 1. The distribution of urocortin- (UCN) containing neurons in pigeon brain and in the nucleus of Edinger-Westphal (EWN). Digital images of coronal sections of the mesodiencephalic transition area in the pigeon brain. With a specific antibody against UCN many UCN+ neurons may be seen forming two medial columns (indicated by arrows) located at the dorsal portion of the substantia grisea centralis (A and B). The main group of the UCN-labeled neurons forms a wing-like structure just below the central aqueductus, at the caudal hypothalamus. The image in B presents a detail of the UCN+ neuron position, medially running over the nucleus interstitialis (IS). The next serial section stained with Giemsa (C) permitted us to identify that the pigeon brain area where UCN+ neurons were found corresponds to the nucleus of Darkschewitsch (ND). The image in D represents a caudal level of the pigeon brain stained with Giemsa where the neurons of the oculomotor complex formed by the dorsal and ventral portions of the oculomotor nucleus (OMd and OMv, respectively) and the EWN are observed. At the level of the images in A, B, and C, no OM or EWN neurons can be seen. Magnification bars: 500 µm (A and D) and 200 µm (B and C). Other abbreviations: FRM = formatio reticularis medialis mesencephali; RU = nucleus ruber.