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Thyrotropin‐releasing hormone immunoreactivity in the brain and the pituitary during Bufo arenarum development
Author(s) -
Miranda Leandro Andrés,
Affanni Jorge Mario
Publication year - 2000
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/s0736-5748(99)00107-0
Subject(s) - median eminence , pars intermedia , diagonal band of broca , endocrinology , medicine , cerebrum , hypothalamus , biology , immunocytochemistry , anatomy , pituitary gland , hormone , central nervous system , basal forebrain
The ontogeny of the thyrotropin releasing hormone (TRH) neuronal system was evaluated by immunocytochemistry in Bufo arenarum . The first appearance of TRH immunoreactive fibers was at early premetamorphosis. These fibers were found in small numbers and weakly stained in the median eminence and pars nervosa. With the advance of larval development, TRH‐like material stained intensely and tended to aggregate in the median eminence, pars nervosa and pars intermedia. At climax stages immunoreactive fibers and perikarya (weakly stained) were also identified in the preoptic area. In adult specimens TRH perikarya and neuronal fibers were found in the preoptic and infundibular nuclei of the hypothalamus and in the amygdala, septum and diagonal band of Broca of the telencephalon. In addition, TRH neuronal fibers and endings were found in the preoptic‐hypophyseal tract, the external zone of the median eminence, the pars nervosa and pars intermedia. Fibers were absent in the pars distalis. This study represents the first immunocytochemical demonstration of TRH in Bufo species, and serves as a basis for clarification of the neuroendocrine regulation of metamorphosis.