Ontogenetic development and neuroanatomical localization of Growth Hormone-Releasing Hormone (GHRH) in the Brain and Pituitary Gland of Pejerrey Odontesthes bonariensis.

MIRANDA, LEANDRO ANDRES; GUSTAVO SOMOZA,; STROBL MAZZULLA, PABLO

INTERNATIONAL JOURNAL OF DEVELOPMENTAL NEUROSCIENCE

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2002 vol. 20 p. 503 - 510

0736-5748

The presence and distribution of growth hormone-releasing hormone (GHRH) were studied by immunocytochemistry in adult and developing pejerrey fish, Odontesthes bonariensis (Atheriniformes).Afewperikarya and fibers with immunoreactivity toGHRH(ir-GHRH) were identified in the olfactory bulbs at hatching. One week later, scattered ir-GHRH cell bodies were observed in the preoptic area and some fibers were detected entering the pituitary gland. Isolated ir-GHRH perikarya were revealed in the hypothalamus and in the medulla oblongata (MO) 3 weeks after hatching. Seven weeks after hatching, ir-GHRH cells were also identified in the nucleus of the lateralOdontesthes bonariensis (Atheriniformes).Afewperikarya and fibers with immunoreactivity toGHRH(ir-GHRH) were identified in the olfactory bulbs at hatching. One week later, scattered ir-GHRH cell bodies were observed in the preoptic area and some fibers were detected entering the pituitary gland. Isolated ir-GHRH perikarya were revealed in the hypothalamus and in the medulla oblongata (MO) 3 weeks after hatching. Seven weeks after hatching, ir-GHRH cells were also identified in the nucleus of the lateralmedulla oblongata (MO) 3 weeks after hatching. Seven weeks after hatching, ir-GHRH cells were also identified in the nucleus of the lateral(MO) 3 weeks after hatching. Seven weeks after hatching, ir-GHRH cells were also identified in the nucleus of the lateral lemniscus and the cerebellum. Both nuclei presented strong ir-GHRH projections extending rostro-ventrally. At 11 weeks after hatching another group of ir-GHRH cells were revealed in the midbrain tegmentum. After that time the pattern of distribution of ir-GHRH structures remained unchanged. At 1 week after hatching and later, the pituitary gland consistently revealed ir-GHRH cells and fibers mainly in theand the cerebellum. Both nuclei presented strong ir-GHRH projections extending rostro-ventrally. At 11 weeks after hatching another group of ir-GHRH cells were revealed in the midbrain tegmentum. After that time the pattern of distribution of ir-GHRH structures remained unchanged. At 1 week after hatching and later, the pituitary gland consistently revealed ir-GHRH cells and fibers mainly in thetegmentum. After that time the pattern of distribution of ir-GHRH structures remained unchanged. At 1 week after hatching and later, the pituitary gland consistently revealed ir-GHRH cells and fibers mainly in the proximalis pars distalis and in a minor proportion of the pars intermedia since week 1. The pineal gland showed ir-GHRH cells projecting into the pineal lumen, at week 6 after hatching and later. The pineal stalk and the subcomissural organ also presented ir-GHRH structures. Additionally, ir-GHRH material was found from week 3 to the adult stage in the following extraneural organs: gills, gut, kidney and hepatopancreas. These results represent the anatomical substrate for understanding the physiology of GHRH peptide in pejerrey, adding information on the ontogeny of neural structures expressing GHRH.and in a minor proportion of the pars intermedia since week 1. The pineal gland showed ir-GHRH cells projecting into the pineal lumen, at week 6 after hatching and later. The pineal stalk and the subcomissural organ also presented ir-GHRH structures. Additionally, ir-GHRH material was found from week 3 to the adult stage in the following extraneural organs: gills, gut, kidney and hepatopancreas. These results represent the anatomical substrate for understanding the physiology of GHRH peptide in pejerrey, adding information on the ontogeny of neural structures expressing GHRH.