Search

This immunohistochemical study analyzed the c-Fos expression (c-Fos-ir) induced by galanin injections. Galanin and N-terminal galanin fragment (1-15) induced a significant increase of c-Fos expression (c-ir) within the medulla oblongata 90 min and 6 h. after intracisternal injections. This expression has been studied mainly in the nucleus of the solitary tract and in the ventrolateral medulla showing different temporal profiles for both peptides. The presence of c-Fos-ir in TH-positive cells was analyzed in all the groups. These results may be relevant to understand the role of galanin in several functions including central cardiovascular control.

This immunohistochemical study shows a wide distribution of neuropeptides in the cat amygdala. Neuropeptide Y is present along the whole amygdaloid complex, and fibers and cell bodies containing neuropeptide Y are observed in all the nuclei studied. Leucine-enkephalin-, gastrin-releasing peptide/bombesin-, and calcitonin gene-related peptide-immunoreactive fibers and perikarya are observed only in discrete nuclei of the amygdaloid complex, whereas only fibers -but no cell bodies- containing methionine-enkephalin-Arg6-Gly7-Leu8 have been observed. No immunoreactivity has been found for gamma-melanocyte-stimulating hormone, dynorphin A (1-17), or galanin. These data are compared with those reported in the amygdala of other mammals.

The distribution of adrenocorticotropin hormone/corticotropin-like intermediate lobe peptide was studied in the cat brain stem, using an indirect immunoperoxidase technique. No immunoreactive cell bodies were observed. However, a high density of immunoreactive fibers was found in the periaqueductal gray, the dorsal nucleus of the raphe, the locus coeruleus, and the marginal nucleus of the brachium conjunctivum. A moderate density was found in the central linear nucleus, the central tegmental field, the Kolliker-Fuse nucleus, the inferior central nucleus, and the postpyramidal nucleus of the raphe. A low density was found in the superior and inferior colliculi, the interpeduncular nucleus, the nucleus sagulum, the superior central nucleus, the cuneiform nucleus, the accessory dorsal tegmental nucleus, the nucleus of the solitary tract, the dorsal motor nucleus of the vagus, and the paralemniscal, magnocellular, gigantocellular, and lateral tegmental fields. Moreover, single immunoreactive fibers were observed in numerous nuclei of the cat brain stem. In comparison with previous studies carried out in the same region of the cat, as well as the rat and the human, our results point to a more widespread distribution of adrenocorticotropin hormone/corticotropin-like intermediate lobe peptide immunoreactive structures in the cat brain stem. This widespread distribution indicates that the peptide might be involved in several physiological functions of the cat brain stem.

Using an indirect immunoperoxidase technique, we studied the location of alpha-melanocyte-stimulating hormone-like fibers and cell bodies in the cat diencephalon. In the thalamus, almost all the immunoreactive fibers were found in the midline region, whereas in the hypothalamus immunoreactive fibers were observed in the whole structure. The hypothalamus showed a higher density of both immunoreactive fibers and cell bodies; no immunoreactive neurons were found in the thalamus. The densest network of immunoreactive fibers was observed in the epithalamus (nucleus periventricularis anterior) and in the hypothalamic nuclei filiformis, hypothalami ventromedialis, arcuatus, periventricularis hypothalami, area hypothalamica dorsalis, and hypothalamus posterior. A high density of immunoreactive neurons was found in the nucleus arcuatus, in the hypothalamus lateralis, and in the area hypothalamica dorsalis; a low density was found in the nucleus hypothalami ventromedialis and in the hypothalamus dorsomedialis. By comparison with the studies of previous researchers, these data showed a more widespread distribution of alpha-melanocyte-stimulating hormone-like immunoreactive fibers and perikarya in the feline hypothalamus. Moreover, our findings indicate that the peptide is widely distributed in the cat diencephalon, suggesting that alpha-melanocyte-stimulating hormone might be involved in several physiological functions.

This paper examines the distribution of fibers and cell bodies containing alpha-neo-endorphin in the cat brain stem by using an indirect immunoperoxidase technique. A high or moderate density of immunoreactive cell bodies was found in the superior central nucleus, nucleus incertus, dorsal tegmental nucleus, nucleus of the trapezoid body, and in the laminar spinal trigeminal nucleus, whereas a low density of such perikarya was observed in the inferior colliculus, nucleus praepositus hypoglossi, dorsal nucleus of the raphe, nucleus of the brachium of the inferior colliculus, and in the nucleus of the solitary tract. The highest density of immunoreactive fibers was found in the substantia nigra, dorsal motor nucleus of the vagus, nucleus coeruleus, lateral tegmental field, marginal nucleus of the brachium conjunctivum, and in the inferior and medial vestibular nuclei. These results indicate that alpha-neo-endorphin is widely distributed in the cat brain stem and suggest that the peptide could play an important role in several physiological functions, e.g., those involved in respiratory, cardiovascular, auditory, and motor mechanisms.

We studied the distribution of cell bodies and fibers containing neurotensin in the brainstem of the cat using an indirect immunoperoxidase technique. A high or moderate density of immunoreactive perikarya was found in the interpeduncular nucleus, inferior colliculus, nucleus of the brachium of the inferior colliculus and in the lateral tegmental field. Moreover, a high density of neurotensin-immunoreactive fibers was observed in the periaqueductal gray, locus coeruleus and in the marginal nucleus of the brachium conjunctivum. The interpeduncular nucleus, nucleus of the solitary tract and the dorsal motor nucleus of the vagus contained a moderate density of immunoreactive fibers.

Using an indirect immunoperoxidase technique, the location of neurotensin-like fibers and cell bodies was studied in the diencephalon of the cat. The findings showed that the hypothalamus is richer in neurotensin-like-immunoreactive structures than the thalamus, and that neurotensin-like-immunoreactive structures are more widely distributed in the hypothalamus than in the thalamus. A high density of immunoreactive fibers was observed in the hypothalamic regions, area hypothalamica dorsalis, hypothalamus posterior, nucleus (n.) filiformis and n. arcuatus, whereas a moderate density was found in the n. parafascicularis, n. paraventricularis anterior, hypothalamus lateralis, median eminence and n. paraventricularis hypothalami. Other diencephalic regions such as n. lateralis posterior, n. lateralis dorsalis, n. medialis dorsalis, n. habenularis lateralis, n. centrum medianum, n. rhomboidens, n. reuniens, hypothalamus anterior, n. supra chiasmaticus, hypothalamus ventromedialis, n. supraopticus and hypothalamus dorsomedialis had the lowest density of immunoreactive fibers. In addition, the densest clusters of neurotensin-like perikarya were found in the n. arcuatus, n. centralis medialis and hypothalamus posterior, whereas the n. medialis dorsalis, n. paraventricularis anterior, n. reuniens, hypothalamus lateralis and hypothalamus ventromedialis had the lowest density. In the n. lateralis dorsalis, n. supraopticus, area hypothalamica dorsalis and n. supra chiasmaticus the density of immunoreactive perikarya was moderate.