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Immunohistochemical localization of chicken gonadotropin‐releasing hormones I and II (cGnRH I and II) in turkey hen brain
Author(s) -
Millam James R.,
Faris Patricia L.,
Youngren Orlan M.,
El Halawani Mohamed E.,
Hartman Boyd K.
Publication year - 1993
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903330106
Subject(s) - nucleus , biology , median eminence , stria terminalis , gonadotropin releasing hormone , anatomy , hypothalamus , medicine , endocrinology , neuroscience , hormone , luteinizing hormone
The distribution of cells and fibers immunoreactive (ir) for either chicken gonadotropin‐releasing hormone I (cGnRH I; [Gln 8 ]GnRH) or II ([His 5 , Trp 7 , Tyr 8 ]GnRH) was determined in brains of turkey hens to reveal whether these peptides occur in separate neuronal systems. ir‐cGnRH I cells were located: along the medial aspect of the ventriculus lateralis, nucleus accumbens, and bed nucleus of the stria terminalis; ventral to the tractus septomesencephalicus and extending medially to the third ventricle, and caudally into the lateral hypothalamic area; and in a diffuse band extending from the nucleus preopticus medialis to the nucleus dorsomedialis anterior thalami. cGnRH I fibers were evident in these areas in addition to the hippocampus, nucleus subhabenularis medialis, nucleus ventromedialis hypothalami, and median eminence. Two groups of ir‐cGnRH II cells were observed: a magnocellular group lying between the substantia grisea centralis and the nucleus ruber; and a parvicellular group lying medial to the nucleus of the basal optic root and extending into the lateral hypothalamic area. ir‐cGnRH II fibers were prominent in limbic structures (cortex piriformis, lateral to nucleus taeniae, hippocampus); olfactory areas (tuberculum olfactorium, nucleus subhabenularis lateralis, nucleus septalis lateralis); areas that in other avian species have steroid‐concentrating cells or receptors (medial edge of lobus parolfactorius, nucleus septalis medialis, nucleus periventricularis magnocellularis, nucleus dorsomedialis posterior thalami); and areas containing ir‐GnRH I cells or fibers but not in median eminence. These results suggest that cGnRH I and II occur in separate neuronal systems and that cGnRH II does not directly promote pituitary gonadotropin secretion. © 1993 Wiley‐Liss, Inc.