Distribution pattern of Neuropeptide Y in the brain, pituitary and olfactory system during the larval development of the toad Chaunus arenarum (Amphibia: Anura).

HEER, T; POZZI, A. G; YOVANOVICH, C; PAZ, D. A

ANATOMIA HISTOLOGIA EMBRYOLOGIA-JOURNAL OF VETERINARY MEDICINE SERIES C

Blackwell

Lugar: Munich; Año: 2008

0340-2096

The first NPY-immunoreactivity (-ir) in the central nervous system of Chaunus arenarum was obtained just after hatching in the preoptic area, ventral thalamus and rostral rhombencephalon. During premetamorphosis, new NPY-ir cells were observed in other brain areas such as pallium, septum and striatum, infundibulum and pars intermedia of the pituitary. Further maturation continued through prometamorphosis with the appearance of cell groups in the diagonal band, amygdala, preoptic nucleus, dorsal nucleus of the habenula, anterior ventral and dorsal thalamus, suprachiasmatic nucleus, tuberculum posterior, tectum, torus semicircularis, interpeduncular nucleus and median eminence. During the metamorphic climax and soon after, the relative abundance of NPY-ir fibers decreased in all hypothalamic areas and the staining intensity and number of NPY-ir cells in the pallium also decreased whereas no cells were found in the striatum, dorsal nucleus of the habenula and tectum. In the olfactory epithelium, nerve or bulb, neither cells nor NPY-ir fibers were found during the stages of development analyzed. The ontogeny pattern of the NPY-ir neuronal system in the brain of Ch. arenarum is more similar to the spatiotemporal appearance reported for Rana esculenta than to that reported for Xenopus laevis. Many NPY-ir fibers were found in the median eminence and in the pars intermedia of the pituitary, supporting the idea that this neuropeptide may play a role in the modulation of hypophyseal secretion during development.