Immunocytochemical identification of CRF-like and SRIF-like peptides in the brain and the pituitary of cyprinid fish

Abstract

Single and double immunocytochemical techniques were applied to the brain and pituitary of carps and goldfish. With the use of antiserum raised against synthetic corticotropin-releasing factor (CRF), immunoreactive perikarya were observed in the nucleus praeopticus and the nucleus praeopticus periventricularis. CRF-like-immunoreactive hypothalamic nerve fibers reach the pituitary. In cyprinids, some fine fibers enter the rostral neurohypophysis bordered by prolactin- and ACTH cells. Other thicker fibers extend ventrocaudally into the neurointermediate lobe. This CRF-like system appears to differ from the SRIF-like system, which is restricted to the proximal pars distalis of the pituitary containing somatotrophs.

Immunocytochemical localization of somatostatin and autoradiographic distribution of somatostatin binding sites in the brain of the African lungfish,Protopterus annectens

“…In the telencephalon, a moderate number of immunoreactive perikarya was found in the medial subpallium of the lungfish (this study) and the frog Andersen et al, 1992), whereas in teleost fish, somatostatin-containing neurons have been observed in the nucleus entopeduncularis of tilapia (Grau et al, 1985), carp, and goldfish (Olivereau et al, 1984b). In the telencephalon of mammals, somatostatin-immunoreactive neurons are far more widely distributed than in other vertebrate groups.…”

Neuroanatomical Substrate for the Inhibition of Gonadotrophin Secretion in Goldfish: Existence of a Dopaminergic Preoptico-Hypophyseal Pathway

“…Martinoli, P. Dubourg, M. Geffard, unpublished ob servations]. In addition, the pituitary receives fibers, not characterized ultrastructurally, and containing different peptides, such as corticotropin-releasing factor (CRF) or somatostatin, some of which likely originate from the pre optic region [19,30]: however, on the basis of in vivo and in vitro studies, there is no evidence for influences of cortico tropin-releasing factor or somatostatin on GTH secretion in goldfish [T. Marchant and R. Peter, unpublished results]. Cell bodies reacting to antibodies to tGnRH and projecting to the pituitary were also reported in the lateroventral pre optic region of the goldfish [24].…”

Immunocytochemical localization of corticotropin-releasing factor in the brain of the turtle, Mauremys caspica

“…In birds the hypothalamic CRF system is quite similar to mammals, although the CRF-IR neurons extend far beyond the boundaries of the PVN proper (P6czely and Antoni 1984; Bugnon et al 1984;Yamada and Mikami 1985;Bons et al 1988;Ball et al 1989). In amphibians and fish this system, consisting of CRF-IR cells located in the preoptic nucleus, projects to the median eminence or neural lobe (Bugnon et al 1984;Olivereau et al 1984Olivereau et al , 1987Tonon et al 1985;Yulis and Lederis 1987;Olivereau and Olivereau 1988;Vallarino et al 1989).…”

“…A hypothalamo-hypophysial portal system does not exist, and CRF acts in a paracrine fashion (Bugnon et al 1983;Olivereau et al 1984;Yulis and Lederis 1987;Olivereau and Olivereau 1988;Vallarino et al 1989). In amphibians, most CRF fibers end in the median eminence close to ACTH cells in the rostral pars distalis.…”

“…The distribution of CRF-IR cells and fibers has also been studied in other vertebrates such as fishes (Bugnon et al 1984;Olivereau et al 1984Olivereau et al , 1987Yulis and Lederis 1987;Olivereau and Olivereau 1988;Vallarino et al 1989), amphibians (Bugnon et al 1984;Tonon et al 1985;Olivereau et al 1987) and birds (P~czely and Antoni 1984; Bugnon et al 1984;Yamada and Mikami 1985;Bons et al 1988;Ball et al 1989). CRF-IR material has also been detected in invertebrates (Remy et al 1982).…”