[Morphofunctional characteristics of serotonin-like neurons in the hypothalamus of rats in ontogeny].
An attempt has been made to reveal 5-HT immunopositive (IP) neurones in the hypothalamus of intact foetuses (18th day of gestation) and neonatal (9-day) rats under normal conditions and after their treatment with drugs involved into 5-HT metabolism or into regulation of its uptake by serotoninergic neurones. 5-HTIP cells were not observed in intact animals as well as after L-tryptophan treatment, whereas two large colonies of these neurones were found in the anterio-lateral hypothalamus and dorsomedial nucleus after subsequent injections of monoamine oxidase inhibitor, pargyline, and amino acid precursor of 5-HT synthesis, L-tryptophan. Significantly less intensive reaction was observed after injections of another precursor of 5-HT synthesis, 5-hydroxytryptophan, or pargyline only. Immunostaining evoked by pargyline or L-tryptophan can be prevented by preliminary injections of fluoxetine, a specific inhibitor of 5-HT uptake by serotoninergic neurones. These data suggest that the immunostaining of hypothalamic neurones is due to their capacity to take up specifically 5-HT from the environment rather than to its intraneuronal synthesis from L-tryptophan. However, 5-HT synthesis from 5-hydroxytryptophan in the same cells may also take place. The uptake of extracellular 5-HT by catecholaminergic neurones is absent, since nomifensine, a specific inhibitor of this uptake, does not affect immunostaining.
Ugriumov
M V
MV
Taxi
J
J
Steinbusch
H W
HW
Tramu
G
G
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D005333:Fetus; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology*; D007150:Immunohistochemistry; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000502:physiology*; D014364:Tryptophan / Q000494:pharmacology
D008996:Monoamine Oxidase Inhibitors; D011985:Receptors, Serotonin; D012701:Serotonin; D014364:Tryptophan; D006916:5-Hydroxytryptophan
Morfofunktsional'naia kharakteristika serotoninopodobnykh neĭronov v gipotalamuse krys v ontogeneze.