Pharmacological evidence for the existence of multiple functional pools of brain serotonin: analysis of brain perfusate from conscious rats.
The serotonin reuptake inhibitor fluoxetine significantly reduced levels of endogenous 5-hydroxyindoleacetic acid (5-HIAA) in brain perfusate of rats implanted with push-pull cannulas. This occurred in conjunction with its suppressant effect upon fixed-ratio operant behavior. Behavior suppressed with the serotonin agonist lysergic acid diethylamide (LSD) occurred in conjunction with a reduction of 5-HIAA only after 5-HIAA was elevated, shortly before, by 5 mg/kg of the serotonin precursor 5-hydroxytryptophan. Our data demonstrate the likely existence of multiple functional pools of serotonin in brain and support the notion that LSD preferentially affects a newly synthesized pool of this transmitter.
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004347:Drug Interactions; D005473:Fluoxetine / Q000494:pharmacology; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology; D008297:Male; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
D005473:Fluoxetine; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D008238:Lysergic Acid Diethylamide; D006916:5-Hydroxytryptophan