Distribution of gonadotropin-releasing hormone immunoreactivity in the brain of Ichthyophis beddomei (Amphibia: Gymnophiona).
From a comparative viewpoint, we have investigated the presence and neuroanatomical distribution of gonadotropin-releasing hormone (GnRH)-immunoreactive material in the brain of a gymnophione amphibian, Ichthyophis beddomei. Immunocytochemical analysis of the adult brain and terminal nerves in both sexes shows the presence of neurons and fibers containing mammalian GnRH (mGnRH)- and chicken GnRH-II (cGnRH-II)-like peptides. With respect to GnRH-immunoreactive material, there are two distinct neuronal systems in the brain: one containing mGnRH, which is located in the forebrain and terminal nerve, and the other containing cGnRH-II, which is restricted to the midbrain tegmentum. Basically, this distribution pattern parallels that of many species of anurans and a urodele. Whereas the presence of cGnRH-II-immunoreactive fibers in the dorsal pallium of L. beddomei is a feature in common with a urodele amphibian, the total absence of cGnRH-II-like material in the median eminence is unique to this species. It is suggested here that the distribution profile of GnRH-like material within the brain and terminal nerve of I. beddomei represents a primitive pattern.
Pinelli
C
C
Dipartimento di Zoologia, Università di Napoli Federico II, Italy.
D'Aniello
B
B
Fiorentino
M
M
Bhat
G
G
Saidapur
S K
SK
Rastogi
R K
RK
D000663:Amphibians / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000166:cytology / Q000648:ultrastructure; D001923:Brain Chemistry / Q000502:physiology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009412:Nerve Fibers / Q000378:metabolism; D009474:Neurons / Q000378:metabolism
D007987:Gonadotropin-Releasing Hormone