Effects of acute fluoxetine on extracellular serotonin levels in the raphe: an in vivo microdialysis study.
Acute administration of fluoxetine (1, 10 and 20 mg/kg i.p.) increased extracellular levels of serotonin (5-hydroxytryptamine, 5-HT) in the frontal cortex, ventral hippocampus and raphe nuclei as measured by in vivo microdialysis in anaesthetized rats. In the frontal cortex, fluoxetine showed a marked dose-response effect whereas in the ventral hippocampus and raphe nuclei the fluoxetine-induced effect was maximum at 10 mg/kg. However, the maximal increase in 5-HT was observed in the cell body-containing area, the raphe nuclei. The order of changes in extracellular 5-HT was raphe nuclei > ventral hippocampus > frontal cortex. Our results add further arguments in favour of the key role played by raphe nuclei in the mechanism of action of serotoninergic antidepressant drugs.
Malagié
I
I
Faculté de Pharmacie, Laboratorie de Pharmacologie JE 92-372, Chatenay-Malabry, France.
Trillat
A C
AC
Jacquot
C
C
Gardier
A M
AM
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005473:Fluoxetine / Q000494:pharmacology*; D005625:Frontal Lobe / Q000187:drug effects* / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D011903:Raphe Nuclei / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*
D005473:Fluoxetine; D012701:Serotonin