Fluvoxamine preferentially increases extracellular 5-hydroxytryptamine in the raphe nuclei: an in vivo microdialysis study

Eur J Pharmacol. 1992 Dec 8;229(1):101-3. doi: 10.1016/0014-2999(92)90292-c.


The effects of systemic administration of fluvoxamine on extracellular serotonin (5-hydroxytryptamine, 5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in the frontal cortex and raphe nuclei of freely moving rats were examined. Fluvoxamine significantly increased extracellular 5-HT concentrations in both regions at the two doses used (1 and 10 mg/kg i.p.). However, the increase in the raphe nuclei was several-fold that in the frontal cortex. Dialysate 5-HIAA concentrations decreased after treatment with fluvoxamine. These results confirm that 5-HT uptake inhibitors preferentially increase extracellular concentrations of 5-HT in the vicinity of cell bodies and dendrites of serotonergic neurones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dialysis
  • Extracellular Space / drug effects
  • Extracellular Space / metabolism
  • Fluvoxamine / administration & dosage
  • Fluvoxamine / pharmacology*
  • Frontal Lobe / drug effects
  • Frontal Lobe / metabolism
  • Hydroxyindoleacetic Acid / metabolism
  • Injections, Intraperitoneal
  • Raphe Nuclei / drug effects*
  • Raphe Nuclei / metabolism
  • Rats
  • Serotonin / metabolism*


  • Serotonin
  • Hydroxyindoleacetic Acid
  • Fluvoxamine