Growing evidence suggests that gonadotropin-inhibitory hormone (GnIH) may play a key role in mediating vertebrate reproduction. GnIH inhibits gonadotropin synthesis and release by decreasing the activity of gonadotropin-releasing hormone (GnRH) neurons as well as by directly regulating gonadotropin secretion from the pituitary. Whereas the presence of GnIH has been widely investigated in various classes of vertebrates, there are very few immunohistochemical reports focusing on GnIH in amphibians. The aim of this study was to assess the presence and neuroanatomical distribution of GnIH-like immunoreactivity in the brain of the anuran amphibian Pelophylax (Rana) esculentus (esculenta) and to explore any potential anatomical relationship with mammalian GnRH-immunoreactive (mGnRH-ir) elements. The GnIH-like immunoreactive (GnIH-ir) system constitutes two distinct subpopulations in the telencephalon and diencephalon, with the highest number of immunoreactive cells located in the preoptic and suprachiasmatic areas. GnIH-ir neurons were also observed in the medial septum, anterior commissure, dorsal hypothalamus, periventricular nucleus of the hypothalamus and posterior tuberculum. Scattered GnIH-ir fibers were present in all major subdivisions of the brain, but only occasionally in the median eminence. Mammalian GnRH-ir neurons were distributed in the mediobasal telencephalon, medial septal area and anterior preoptic area. Double-label immunohistochemistry revealed that the GnRH and GnIH systems coexist and have overlapping distributions at the level of the anterior preoptic area. Some GnIH-ir fibers were in close proximity to mGnRH-ir cell bodies. Our results suggest that both the neuroanatomy and the functional regulation of GnRH release are conserved properties of the hypothalamic GnIH-ir system among vertebrate species.

Growing evidence suggests that gonadotropin-inhibitory hormone (GnIH) may play a key role in mediating vertebrate reproduction. GnIH inhibits gonadotropin synthesis and release by decreasing the activity of gonadotropin-releasing hormone (GnRH) neurons as well as by directly regulating gonadotropin secretion from the pituitary. Whereas the presence of GnIH has been widely investigated in various classes of vertebrates, there are very few immunohistochemical reports focusing on GnIH in amphibians. The aim of this study was to assess the presence and neuroanatomical distribution of GnIH-like immunoreactivity in the brain of the anuran amphibian Pelophylax (Rana) esculentus (esculenta) and to explore any potential anatomical relationship with mammalian GnRH-immunoreactive (mGnRH-ir) elements. The GnIH-like immunoreactive (GnIH-ir) system constitutes two distinct subpopulations in the telencephalon and diencephalon, with the highest number of immunoreactive cells located in the preoptic and suprachiasnnatic areas. GnIH-ir neurons were also observed in the medial septum, the anterior commissure, the dorsal hypothalamus, the periventricular nucleus of the hypothalamus, and the posterior tuberculum. Scattered GnIH-ir fibers were present in all major subdivisions of the brain but only occasionally in the median eminence. mGnRH-ir neurons were distributed in the mediobasal telencephalon, the medial septal area, and the anterior preoptic area. Double-label immunohistochemistry revealed that the GnRH and GnIH systems coexist and have overlapping distributions at the level of the anterior preoptic area. Some GnIH-ir fibers were in close proximity to mGnRHir cell bodies. Our results suggest that both the neuroanatomy and the functional regulation of GnRH release are conserved properties of the hypothalamic GnIH-ir system among vertebrate species. (C) 2014 S. Karger AG, Basel

Neuroanatomical Organization of the Brain Gonadotropin-Inhibitory Hormone and Gonadotropin-Releasing Hormone Systems in the Frog Pelophylax esculentus

PINELLI, Claudia
;
2015

Abstract

Growing evidence suggests that gonadotropin-inhibitory hormone (GnIH) may play a key role in mediating vertebrate reproduction. GnIH inhibits gonadotropin synthesis and release by decreasing the activity of gonadotropin-releasing hormone (GnRH) neurons as well as by directly regulating gonadotropin secretion from the pituitary. Whereas the presence of GnIH has been widely investigated in various classes of vertebrates, there are very few immunohistochemical reports focusing on GnIH in amphibians. The aim of this study was to assess the presence and neuroanatomical distribution of GnIH-like immunoreactivity in the brain of the anuran amphibian Pelophylax (Rana) esculentus (esculenta) and to explore any potential anatomical relationship with mammalian GnRH-immunoreactive (mGnRH-ir) elements. The GnIH-like immunoreactive (GnIH-ir) system constitutes two distinct subpopulations in the telencephalon and diencephalon, with the highest number of immunoreactive cells located in the preoptic and suprachiasnnatic areas. GnIH-ir neurons were also observed in the medial septum, the anterior commissure, the dorsal hypothalamus, the periventricular nucleus of the hypothalamus, and the posterior tuberculum. Scattered GnIH-ir fibers were present in all major subdivisions of the brain but only occasionally in the median eminence. mGnRH-ir neurons were distributed in the mediobasal telencephalon, the medial septal area, and the anterior preoptic area. Double-label immunohistochemistry revealed that the GnRH and GnIH systems coexist and have overlapping distributions at the level of the anterior preoptic area. Some GnIH-ir fibers were in close proximity to mGnRHir cell bodies. Our results suggest that both the neuroanatomy and the functional regulation of GnRH release are conserved properties of the hypothalamic GnIH-ir system among vertebrate species. (C) 2014 S. Karger AG, Basel
2015
Growing evidence suggests that gonadotropin-inhibitory hormone (GnIH) may play a key role in mediating vertebrate reproduction. GnIH inhibits gonadotropin synthesis and release by decreasing the activity of gonadotropin-releasing hormone (GnRH) neurons as well as by directly regulating gonadotropin secretion from the pituitary. Whereas the presence of GnIH has been widely investigated in various classes of vertebrates, there are very few immunohistochemical reports focusing on GnIH in amphibians. The aim of this study was to assess the presence and neuroanatomical distribution of GnIH-like immunoreactivity in the brain of the anuran amphibian Pelophylax (Rana) esculentus (esculenta) and to explore any potential anatomical relationship with mammalian GnRH-immunoreactive (mGnRH-ir) elements. The GnIH-like immunoreactive (GnIH-ir) system constitutes two distinct subpopulations in the telencephalon and diencephalon, with the highest number of immunoreactive cells located in the preoptic and suprachiasmatic areas. GnIH-ir neurons were also observed in the medial septum, anterior commissure, dorsal hypothalamus, periventricular nucleus of the hypothalamus and posterior tuberculum. Scattered GnIH-ir fibers were present in all major subdivisions of the brain, but only occasionally in the median eminence. Mammalian GnRH-ir neurons were distributed in the mediobasal telencephalon, medial septal area and anterior preoptic area. Double-label immunohistochemistry revealed that the GnRH and GnIH systems coexist and have overlapping distributions at the level of the anterior preoptic area. Some GnIH-ir fibers were in close proximity to mGnRH-ir cell bodies. Our results suggest that both the neuroanatomy and the functional regulation of GnRH release are conserved properties of the hypothalamic GnIH-ir system among vertebrate species.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11591/235048
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