In amphibians, as in other vertebrates, luteinizing hormone releasing hormone (LHRH, GnRH) appears to be involved in activating sexual behaviors. LHRH injections can activate reproductive behaviors in at least two species of amphibians (Xenopus laevis and Taricha granulosa). However, other studies, using microdissection and radioimmunoassay procedures to quantify LHRH in T. granulosa, found that ir-LHRH concentrations in the hypothalamus are not correlated (seasonally or individually) with reproductive behaviors. Considering that hypothalamic LHRH may not be behaviorally important, the discovery of extrahypothalamic sites for LHRH immunoreactivity is of interest. Immunocytochemical studies found ir-LHRH in cell bodies and fibers in areas that correspond with the nervus terminalis of amphibians. Furthermore, irLHRH concentrations in the rostral telencephalon of Taricha females were found to increase during the initial stages of courtship. These observations support the following working hypotheses: (1) LHRH is involved in regulating sexual behaviors in some amphibians and (2) LHRH regulates these behaviors by acting in the nervus terminalis to transduce olfactory cues and not by acting in the hypothalamus to stimulate the pituitary-gonad axis.
|Original language||English (US)|
|Number of pages||9|
|Journal||Annals of the New York Academy of Sciences|
|State||Published - 1987|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)