In vivo chronoamperometric measures of extracellular serotonin clearance in rat dorsal hippocampus: Contribution of serotonin and norepinephrine transporters

Research output: Contribution to journalArticle

57 Scopus citations

Abstract

The effects of blockade of serotonin (5-HT) and norepinephrine (NE) transporters (SERT and NET, respectively) on the removal of locally applied 5-HT from extracellular fluid (ECF) were examined using in vivo chronoamperometry. Male Sprague-Dawley rats were anesthetized with chloralose/urethane, and a Nafion-coated, carbon fiber electrode attached to a multibarrel micropipette was positioned into either the dentate gyrus or CA3 region of the dorsal hippocampus. Pressure ejection of 5-HT elicited reproducible electrochemical signals of similar peak amplitude and time course in both structures. Local application of the selective serotonin reuptake inhibitors (SSRI) fluvoxamine and citalopram prolonged the clearance of 5-HT in both brain regions and also increased signal amplitude in the CA3 region. These effects were abolished in rats pretreated with 5,7- dihydroxytryptamine (5,7-DHT), a selective 5-HT neurotoxin. The NE uptake inhibitors desipramine (DMI) and protriptyline did not alter the 5-HT signal in the CA3 region but prolonged the clearance of 5-HT in the dentate gyrus; this effect was absent in rats pretreated with 6-hydroxydopamine (6-OHDA), a selective catecholamine neurotoxin. The prolongation of the removal of 5-HT from the ECF in the dentate gyrus caused by fluvoxamine or desipramine was of comparable magnitude and was dose dependent. Furthermore, per picomole of 5- HT applied, the signal amplitude and clearance time were significantly increased in the dentate gyrus of rats lesioned with either 5,7-DHT or 6- OHDA. Only 5,7-DHT treatment caused this effect in the CA3 region. From these data, it is inferred that in certain regions of brain (dentate gyrus), both the SERT and NET contribute to the active clearance of exogenously applied 5- HT.

Original languageEnglish (US)
Pages (from-to)967-976
Number of pages10
JournalJournal of Pharmacology and Experimental Therapeutics
Volume286
Issue number2
StatePublished - 1998

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmacology

Fingerprint Dive into the research topics of 'In vivo chronoamperometric measures of extracellular serotonin clearance in rat dorsal hippocampus: Contribution of serotonin and norepinephrine transporters'. Together they form a unique fingerprint.

  • Cite this