Modification of gonadotropin releasing hormone (GnRH) mRNA expression in the retinal-recipient Thalamus.
Gen Comp Endocrinol
; 106(2): 251-64, 1997 May.
Article
en En
| MEDLINE
| ID: mdl-9169121
Although the environmental cues that trigger reproductive behaviors are known for many species, the mechanisms through which these signals influence the neurochemistry of the brain to produce behavior have been elusive. In this study, we describe a retinally modulated system of gonadotropin releasing hormone (GnRH) producing neurons in the thalamus of the plainfin midshipman fish, Porichthys notatus. Previously, we cloned and sequenced the cDNA for prepro-GnRH in midshipman. Here, using in situ hybridization, we localized prepro-GnRH mRNA to the ventrolateral nucleus of the thalamus, three divisions of the preoptic area, the ganglion of the terminal nerve, and the olfactory bulb. Since the thalamus, terminal nerve ganglion, and preoptic area have been associated with visual functions, we investigated the retinal connections in midshipman. In particular, biocytin tract tracing delineated a reciprocal connection between the ventrolateral nucleus of the thalamus and the retina. Retinofugal projections are exclusively contralateral. Experimental manipulation of this retinalthalamic loop through complete optic nerve transection shows that GnRH mRNA expression in the contralateral ventrolateral nucleus may be influenced by the retina. We hypothesize that a reciprocal retinothalamic GnRH circuit is important in modulating the expression of seasonal reproductive behaviors.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Retina
/
Tálamo
/
ARN Mensajero
/
Hormona Liberadora de Gonadotropina
/
Peces
Límite:
Animals
Idioma:
En
Revista:
Gen Comp Endocrinol
Año:
1997
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos