Ontogenetic development of gonadotropin-releasing hormone-like immunoreactive neurons in the brain of the chum salmon, Oncorhynchus keta.
In the chum salmon, gonadotropin-releasing hormone-immunoreactive (GnRH-ir) cells were first detected in the olfactory placode of embryos at 16 days after fertilization, and then appeared sequentially in the olfactory nerve and the distal part of the forebrain by hatching. Four months after hatching, the terminal nerve was differentiated along the olfactory nerve, and GnRH-ir fibers extended to the hypothalamus and hypophysis. GnRH-ir cells occurred later in the preoptic area in about 1-year-old juveniles. These data suggest that GnRH neurons originate in the olfactory placode and then migrate into the brain along the olfactory nerve.
Chiba
A
A
Department of Biology, School of Dentistry at Niigata, Nippon Dental University, Japan.
Oka
S
S
Honma
Y
Y
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis / Q000096:biosynthesis*; D007031:Hypothalamus / Q000254:growth & development / Q000378:metabolism; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism*; D009832:Olfactory Nerve / Q000254:growth & development / Q000378:metabolism; D017683:Oncorhynchus; D010902:Pituitary Gland / Q000254:growth & development / Q000378:metabolism; D011301:Preoptic Area / Q000254:growth & development / Q000378:metabolism; D016548:Prosencephalon / Q000254:growth & development / Q000378:metabolism
D007987:Gonadotropin-Releasing Hormone