Subpopulations of migrating neurons express different levels of LHRH in quail and chick embryos.
LHRH neurons of the septal-preoptic area originate in the olfactory placode and migrate in the olfactory nerve into the brain during embryonic development. In adult birds, LHRH neurons have been found in the septal-preoptic area, mesencephalon and more recently in the lateral anterior nucleus of the thalamus (LA). LHRH neurons of the LA do not originate in the olfactory placode. Using immunocytochemistry, we examined the distribution of LHRH neurons in the embryonic and adult quail nervous system. The pattern of LHRH immunostaining in quail embryos was similar to that seen in chick embryos. However, there were many fewer neurons immunostained for LHRH from the olfactory placode to the septal-preoptic area in quail than in chick embryos. In contrast, there were more labeled neurons and more intense LHRH immunostaining in the thalamus of the quail than in the thalamus of chick embryos. In agreement with other studies, our data suggest that there are species differences in LHRH expression in migrating neurons. The current results should also be considered for quail-chick chimeras involving the olfactory placode.
Gao
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Department of Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha 68198-6395, USA.
Abou-Nasr
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Norgren
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D000818:Animals; D000918:Antibody Specificity; D002465:Cell Movement / Q000502:physiology*; D002642:Chick Embryo; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009832:Olfactory Nerve / Q000737:chemistry / Q000166:cytology; D011784:Quail; D013687:Telencephalon / Q000166:cytology; D013787:Thalamic Nuclei / Q000737:chemistry* / Q000166:cytology
D007987:Gonadotropin-Releasing Hormone