Somatostatin, neuropeptide Y and galanin: Immunohistochemical detection and mapping of neuropeptide distributions in goldfish brain, with reference to rat.

The biochemical neuroanatomy of the goldfish brain, with some reference to that in the rat brain, was investigated. Retrograde tracing immunofluorescence techniques reveal that the efferents of the somatostatin (SRIF)-positive cells of the entopeduncular nucleus of the rat do not project to the ventroanterior/ventrolateral nuclei of the thalamus. Using of immunohistochemical staining techniques, the distributions of the neurotransmitters SRIF, NPY and galanin (Gal) were mapped throughout the brain of the goldfish. Single-label immunohistochemistry was used to determine the distribution of Gal in the goldfish brain. Gal is present primarily in fibres and terminals but in only a few cell bodies restricted to the preoptic and tuberal hypothalamus and the reticular formation. When the distributions of SRIF, NPY and Gal in the goldfish brain were compared to the literature on brains of other teleost fish and in the mammalian brain, it was clear that they have altered little across species. (Abstract shortened by UMI.