Evidence that taste aversion learning induced by l-5-hydroxytryptophan is mediated peripherally.
Rats learned to avoid a saccharin solution if their initial consumption of it was followed by intraperitoneal (IP) administration of 25 mg/kg l-5-hydroxytryptophan (l-5-HTP); this taste aversion learning did not occur in rats pretreated with 50 mg/kg (IP) of the aromatic l-amino acid decarboxylase inhibitor RO 4-4602 (benserazide). RO 4-4602 antagonized the l-5-HTP-induced elevation of 5-hydroxytryptamine (5-HT) in the mesentery but significantly increased the l-5-HTP-induced elevation of 5-HT in the brain. These results indicate that l-5-HTP-induced taste aversion is correlated with peripheral, but not central, elevation of 5-HT.
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001545:Benserazide / Q000494:pharmacology; D001923:Brain Chemistry / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects; D004327:Drinking Behavior / Q000187:drug effects; D008297:Male; D008643:Mesentery / Q000378:metabolism; D010525:Peripheral Nerves / Q000502:physiology*; D051381:Rats; D012701:Serotonin / Q000378:metabolism; D013649:Taste / Q000502:physiology*
D012701:Serotonin; D001545:Benserazide; D006916:5-Hydroxytryptophan