DISTRIBUTION OF GASTRIN-RELEASING PEPTIDE BOMBESIN-LIKE IMMUNOREACTIVE CELL-BODIES AND FIBERS IN THE BRAIN-STEM OF THE CAT

Using an indirect immunoperoxidase technique, the location of gastrin- releasing/bombesin-like immunoreactive fibres and cell bodies in the c at brainstem was studied. A moderate or low density of immunoreactive cell bodies was observed in the nucleus of the brachium of the inferio r colliculus, pericentral nucleus of the inferior colliculus, ventral nucleus of the lateral lemniscus and in the external division of the l ateral reticular nucleus. The densest network of immunoreactive fibres was visualized in the interpeduncular nucleus, marginal nucleus of th e brachium conjunctivum, alaminar and laminar spinal trigeminal nuclei and in the substantia nigra. The periaqueductal gray, brachium of the inferior colliculus, nucleus of the brachium of the inferior collicul us, locus coeruleus, nucleus incertus, Kolliker-Fuse nucleus, facial n ucleus, medial nucleus of the solitary tract and the area postrema con tained a moderate density of immunoreactive fibres, whereas the perice ntral nucleus of the inferior colliculus, nucleus sagulum, cuneiform n ucleus, dorsal nucleus of the raphe, superior central nucleus, central , lateral and paralemniscal tegmental fields, ventral nucleus of the l ateral lemniscus, dorsal tegmental nucleus, postpyramidal nucleus of t he raphe, nucleus ambiguus, accessory dorsal tegmental nucleus, dorsal motor nucleus of the vagus and the inferior olive had the lowest dens ity of immunoreactive fibres.