Distribution of neuromedin U-like immunoreactivity in the central nervous system of Rana esculenta.

The distribution of perikarya and nerve fibers containing neuromedin U-like immunoreactivity in the brain of Rana esculenta was determined with an antiserum directed toward the carboxyl terminus of the peptide. In the telencephalon, immunoreactive perikarya were found in the olfactory bulb, the medial septum, and the diagonal band. In the diencephalon, labeled perikarya were detected in the anterior and posterior preoptic areas, the dorsal nucleus of the hypothalamus, the caudal part of the infundibulum, and the posterior tuberculum. In the mesencephalon, immunoreactive cell bodies were found only in the laminar nucleus of the torus semicircularis and the anterodorsal tegmental nucleus. In the rhombencephalon, labeled perikarya were detected in the secondary visceral nucleus, the cerebellar nucleus, the central gray, and the nucleus of the solitary tract. Immunoreactive nerve fibers were observed in all areas of the brain that contained labeled perikarya. The densest accumulations were found in the nucleus accumbens; the dorsal part of the lateral septum; the periventricular region of the ventral thalamus; the lateral part of the infundibulum; the anterodorsal, anteroventral, posterodorsal, and posteroventral tegmental nuclei; and the periaqueductal region of the tegmentum. The distribution of neuromedin U-like immunoreactivity in the frog brain was substantially different from the distribution described for the rodent brain.