Neuropeptide tyrosine-like immunoreactivity (NPY-LI) in ganglion neurons in the adrenal gland of the flat snake (Waglerophis merremii)

In previous morphological and histochemical studies on the adrenal gland of the flat snake, no data demonstrating the existence of ganglion neurons has been reported. The aim of this paper was therefore to establish the presence of ganglion neurons in the adrenal gland of the flat snake Waglerophis merremii and, further to study their chemical phenotype using immunohistochemistry. Our results showed the presence of cells which were immunolabelled with the neuronal marker neurofilament 10 and were thus identified as large ganglion neurons. These cells were localized in the dorsal ribbon of the gland, suggesting a noradrenergic phenotype, exhibited long processes with a longitudinal direction and co-expressed neuropeptide tyrosine- (NPY) and tyrosine hydroxylase-like immunoreactivities (-LI).In addition, NPY-immunoreactive (-IR) fibers were recognized with a wide distribution throughout the gland whereas vasoactive intestinal polypeptide (VIP)-IR fibers were only observed between clusters of cortical and adrenergic chromaffin cells. No cells containing VIP-LI were detected within the gland. Based on their histochemical phenotype, ganglion cells containing NPY and TH could correspond to ganglion neurons type I of the rat. The possible absence of type II ganglion neurons in the adrenal gland of the snake is discussed

Galanin-like immunoreactive expression in the central nervous system of the toad

The distribution of galanin (GAL)-like immunoreactivity (-LI) was studied in the CNS of the toad (Bufo arenarum Hensel). Tissue sections were incubated with antibodies directed toward rat or porcine GAL and processed either for the avidin-biotin complex, or for the indirect immunofluorescence techniques. In the telencephalon GAL-immunoreactive (-IR) perikarya were observed in the ventral part of the striatum and in the septal accumbens nuclei. Immunopositive neurons were also observed in the medial amigdala with some intermingled cells between the fibers of the anterior commissure. Numerous GAL-IR perikarya were present along the rostrocaudal medial preoptic nucleus. Occasionally lightly immunoreactive cells were detected in the magnocellular region. The most numerous accumulation of GAL-IR cells was present in the ventral hypothalamus around the infundibular region, in the posterior tubercle and in the nucleus of the paraventricular organ. Immunostained cells were also present in the pretectal gray, solitary nucleus, gracil nucleus and in the spinal cord in the intermediate gray and in large motoneurons of the ventral horn. The widespread distribution found of GAL-LI suggests that GAL in the toad, as well as in mammalian species, may serve a variety of functions with a preponderant role in neuroendocrine processes. A role for GAL as a trophic factor in the brain of the toad is also suggested.