Differential in vivo clearance of serotonin in rat dorsal raphe nucleus and CA3 region

Sylvia Montaez, Lynette C Daws, Georgianna G Gould, Greg A. Gerhardt, Alan Frazer

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

In vivo chronoamperometric recordings were used to determine if the majority of serotonin transporters (SERTs) in the dorsal raphe nucleus (DRN) are functionally active. This was achieved by comparing the clearance of exogenously applied serotonin (5-HT) from the extracellular fluid (ECF) of the DRN to that in the CA3 region of the hippocampus, an area with lower SERT density. Serotonin was pressure ejected into these regions in anesthetized rats and reproducible electrochemical signals measured by carbon fiber microelectrodes were recorded. Consistent with SERT density as measured by [3H]cyanoimipramine binding in these brain regions (DRN≫CA3), clearance of 5-HT was significantly faster in DRN compared to that in the CA3 region. The selective serotonin reuptake inhibitor, fluvoxamine, prolonged 5-HT clearance in both CA3 and DRN. It is known that the norepinephrine transporter (NET) contributes to clearance of 5-HT in the dentate gyrus (DG) but not in CA3. Given that the DRN receives noradrenergic innervation, it was also determined if the NET contributes to 5-HT clearance in the DRN. Destruction of the NET with the neurotoxin 6-hydroxydopamine failed to alter 5-HT clearance parameters in the DRN. These data support the hypothesis that serotonin transporters are functionally active in the DRN, that serotonin clearance is mediated primarily by the SERT in the DRN and that the faster clearance of 5-HT from this region is related to its greater density of functional SERTs.

Original languageEnglish (US)
Pages (from-to)236-244
Number of pages9
JournalBrain Research
Volume955
Issue number1-2
DOIs
StatePublished - Nov 15 2002

Fingerprint

Serotonin
Serotonin Plasma Membrane Transport Proteins
Norepinephrine Plasma Membrane Transport Proteins
Dorsal Raphe Nucleus
Fluvoxamine
Oxidopamine
Extracellular Fluid
Dentate Gyrus
Neurotoxins
Serotonin Uptake Inhibitors
Microelectrodes
Hippocampus
Pressure
Brain

Keywords

  • CA3
  • Chronoamperometry
  • Dorsal raphe nucleus
  • Rat
  • Serotonin transporter

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Differential in vivo clearance of serotonin in rat dorsal raphe nucleus and CA3 region. / Montaez, Sylvia; Daws, Lynette C; Gould, Georgianna G; Gerhardt, Greg A.; Frazer, Alan.

In: Brain Research, Vol. 955, No. 1-2, 15.11.2002, p. 236-244.

Research output: Contribution to journalArticle

Montaez, Sylvia ; Daws, Lynette C ; Gould, Georgianna G ; Gerhardt, Greg A. ; Frazer, Alan. / Differential in vivo clearance of serotonin in rat dorsal raphe nucleus and CA3 region. In: Brain Research. 2002 ; Vol. 955, No. 1-2. pp. 236-244.
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