title: Depletion of central catecholamines alters amphetamine- and fenfluramine-induced taste aversions in the rat.
abstract: Conditioned taste aversions induced by pairing the consumption of saccharin with an amphetamine injection are attenuated in rats with depletion of central catecholamines caused by intraventricular administration of 6-hydroxydopamine (6-OHDA). The hypothesis that dopamine (DA) depletion is responsible for this effect was tested. The reduction in conditioning caused by intraventricular 6-OHDA could not be duplicated either with injections of 6-OHDA into the substantia nigra (Experiment 1) or with intraventricular 6-OHDA injections in animals pretreated with desmethylimipramine (Experiment 2). Both treatments, however, produced large depletions of telencephalic DA. 6-Hydroxydopa infusions caused a preferential loss of telencephalic norepinephrine (NE) but also failed to alter taste aversion learning. It is concluded that the effect of intraventricular 6-OHDA on amphetamine-induced aversions was the result of depletion of both NE and DA. In a third experiment the generality of the effect was examined by pairing saccharin consumption with injections of the amphetamine congener fenfluramine. Depletion of both NE and DA failed to alter fenfluramine-induced aversions. Infusion of 6-OHDA into the substantia nigra, however, retarded the extinction of such an aversion. Evidence is discussed for a peripheral site of action for fenfluramine in the conditioned aversion paradigm.
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D003891:Desipramine / Q000494:pharmacology; D003913:Dextroamphetamine / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D004326:Drinking / Q000187:drug effects; D005277:Fenfluramine / Q000494:pharmacology*; D006892:Hydroxydopamines / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism; D013649:Taste / Q000187:drug effects* / Q000502:physiology; D013687:Telencephalon / Q000187:drug effects / Q000378:metabolism*
chemical_list: D006892:Hydroxydopamines; D005277:Fenfluramine; D003891:Desipramine; D003913:Dextroamphetamine; D004298:Dopamine; D009638:Norepinephrine