Development of the tuberoinfundibular system in rats: birthdates of the tyrosine hydroxylase-immunopositive neurons.
The present study has attempted to determine the birthdates of the tyrosine hydroxylase (TH)-immunopositive neurons in the arcuate nucleus (AN) of rats, thus evaluating the time of the last mitotic divisions of their cell precursors. For this aim, 'long-survival' [3H]thymidine autoradiography was used in combination with immunocytochemistry of TH, the first enzyme of catecholamine synthesis. According to our data, some TH-immunopositive neurons in the AN were born as early as the 13th fetal day. At day 14, the number of double-labeled neurons almost tripled while reaching a maximum at day 15 of the intrauterine development. The fraction of the double-labeled neurons dropped on the following day, and practically disappeared by fetal day 17, showing cessation of the production of the TH-immunopositive neurons. The birth of the TH-immunopositive neurons is considered as the onset of the development of the tuberoinfundibular dopaminergic system.
Borisova
N A
NA
Laboratory of Hormonal Regulations, Russian Academy of Sciences, Moscow.
Ugrumov
M V
MV
Balan
I S
IS
Thibault
J
J
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000196:embryology* / Q000201:enzymology; D001345:Autoradiography; D005260:Female; D005865:Gestational Age; D007150:Immunohistochemistry; D009474:Neurons / Q000201:enzymology* / Q000276:immunology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D016622:Silver Staining; D013936:Thymidine / Q000378:metabolism; D016707:Tissue Fixation; D014446:Tyrosine 3-Monooxygenase / Q000276:immunology / Q000378:metabolism*
D014446:Tyrosine 3-Monooxygenase; D013936:Thymidine