title: The effect of apomorphine on serotonin neurons in dorsal raphe nucleus and catecholamine nerve terminals in paraventricular hypothalamic nucleus. Histofluorescence studies.
abstract: Histofluorescent method was employed to study the intensity of serotonin (5-HT) fluorescence in nucleus raphe dorsalis (DR) and catecholamine (CA) fluorescence in nucleus paraventricularis hypothalami (PVH). Apomorphine (APO, 20 mg/kg) induced, after 30 min, the increase in intensity of 5-HT fluorescence in DR and CA fluorescence in PVH. This increase was prevented by the previous dopamine receptor blockade by spiroperidol (2 mg/kg), administered 1 hr prior to APO. After alpha-methyl-tyrosine (alpha-MT) (2 X 400 mg/kg)-induced decrease in CA level, simultaneous intensification in 5-HT fluorescence was observed in DR. APO administered to those rats decreased the intensity of 5-HT fluorescence in DR, down to the level observed in the controls. This decrease in fluorescence was also prevented by pretreatment with spiroperidol. p-Chlorophenylalanine (PCPA)-induced inhibition in 5-HT synthesis decreased the intensity of 5-HT fluorescence and this decrease was considerably intensified by APO. The obtained results support the following concepts: 1) the effect of apomorphine on 5-HT in DR and on CA in PVH seems, to be indirect, namely through dopamine receptor stimulation, 2) the changes in 5-HT fluorescence in DR are probably connected with the acceleration in this amine turnover.
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects*; D002395:Catecholamines / Q000032:analysis*; D010134:Fenclonine / Q000494:pharmacology; D006652:Histological Techniques; D006801:Humans; D007031:Hypothalamus / Q000032:analysis / Q000187:drug effects*; D008297:Male; D008636:Mesencephalon / Q000032:analysis; D008781:Methyltyrosines / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D012701:Serotonin / Q000032:analysis*; D013134:Spiperone / Q000494:pharmacology; D013239:Stereotyped Behavior / Q000187:drug effects
chemical_list: D002395:Catecholamines; D008781:Methyltyrosines; D012701:Serotonin; D013134:Spiperone; D001058:Apomorphine; D010134:Fenclonine