NEUROPEPTIDES AND MONOAMINES IN THE CARP (CYPRINUS-CARPIO) PRETECTUM - AN IMMUNOCYTOCHEMICAL STUDY

The distribution of neurotensin, neurokinin A, dynorphin A, galanin, s omato-statin-28 (1-12), neuropeptide Y, vasoactive intestinal polypept ide, gastrin-releasing peptide, gamma-melanocyte stimulating hormone, alpha-neo-endorphin, angiotensin II, cholecystokinin-8, serotonin and tyrosine hydroxylase has been studied in the pretectal nuclei of the C yprinus carpio: nuclei pretectalis superficialis parvicellularis and m agnocellularis, pretectalis centralis, pretectalis, and pretectalis pe riventricularis dorsalis and ventralis using an indirect immunoperoxid ase technique. We have found neuropeptide Y and serotonin immunoreacti ve fibres in all pretectal nuclei, whereas gastrin-releasing peptide i mmunoreactive fibres were visualized in the nuclei pretectalis superfi cialis parvicellularis and magnocellularis, pretectalis centralis, pre tectalis and pretectalis periventricularis dorsalis; neurokinin A immu noreactive fibres in the nuclei pretectalis superficialis parvicellula ris and magnocellularis and pretectalis periventricularis dorsalis; ga lanin immunoreactive fibres in the nuclei pretectalis superficialis pa rvicellularis, pretectalis centralis and pretectalis periventricularis dorsalis; and neurotensin immunoreactive fibres in the nucleus pretec talis periventricularis dorsalis. Additionally, immunoreactive cell bo dies containing neuropeptide Y were observed in the nuclei pretectalis superficialis parvicellularis and pretectalis periventricularis dorsa lis, and serotonin and tyrosine hydroxylase. cell bodies were found in the nuclei pretectalis periventricularis dorsalis and ventralis respe ctively. The presence of the neuroactive substances found in the carp pretectal nuclei suggest that they might be involved in the regulation of certain functions within the visual system.