title: Time course of 5,6-dihydroxytryptamine neurotoxic effects on fowl diencephalon and upper brain stem monoaminergic pathways.
abstract: In adult fowls the time-course of the neurotoxic effects of 5,6-DHT on indolaminergic neurons (in comparison with controls and with animals pre-treated with mebanazine, a MAO-inhibitor) was studied. It was shown that 5,6-DHT given into the third cerebral ventricle produced a rather selective degeneration of indolaminergic neurons which was most dramatic 4 and 7 days after the injection. Injured axons characterized by a pile-up of strongly yellow fluorescent material were seen in areas bordering the third ventricle, and in the posterior, medium and anterior hypothalamus, preoptic area, median eminence, n. tuberalis and paleostriatum augmentatum. A decrease in yellow fluorescence in areas distal to the injured axons was only detectable after 19 days. A certain regrowth of some terminal networks was observed 30 days after 5,6-DHT administration. Present data indicate that, in fowls, ascending indolamine neurons mainly originate in tegmental cell bodies and are organized in a large tract which runs along the medial forebrain bundle, sending terminals innervating several diencephalic and other subcortical areas.
mesh_terms: D015115:5,6-Dihydroxytryptamine / Q000494:pharmacology*; D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism; D001931:Brain Mapping; D001933:Brain Stem / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism; D002645:Chickens / Q000033:anatomy & histology*; D004027:Diencephalon / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006651:Histocytochemistry; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009410:Nerve Degeneration / Q000187:drug effects; D009434:Neural Pathways / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D013997:Time Factors
chemical_list: D001679:Biogenic Amines; D002395:Catecholamines; D008996:Monoamine Oxidase Inhibitors; D015115:5,6-Dihydroxytryptamine