Patterns of c-fos expression induced by fluvoxamine are different after acute vs. chronic oral administration.
Fluvoxamine is a selective serotonin (5-HT) reuptake inhibitor (SSRI) with a broad spectrum of behavioral and therapeutic effects, e.g. in depressive illness. We used the expression of c-fos, after both acute and chronic oral administration of fluvoxamine in the rat, to study its immediate and long-term effects, in relation to the distribution of Galanin (GAL) and Vasoactive Intestinal Polypeptide (VIP). After acute oral administration, most consistent increases were apparent in (parts of); the nucleus of the solitary tract, medial part; the lateral parabrachial nucleus, external part; the bed nucleus of the stria terminalis, dorsolateral part; and the central nucleus of the amygdala, lateral part. After chronic administration, distribution of Fos-IR was similar to acute administration, although numbers of Fos-IR neurons were no longer significantly different from control values. It is concluded that activation of 5-HT3-receptors in the caudal brainstem or gastro-intestinal afferents of the vagal nerve may play a role in the observed pattern of Fos-IR after fluvoxamine administration. The relationship with the antidepressant effects of fluvoxamine needs further investigations.
Dept. of Anatomy and Embryology, Fac. of Medical Sciences, University of Nijmegen, Netherlands. J.Veening@anat.kun.nl
J G
JG
Veening
L M
LM
Coolen
W J
WJ
Spooren
H
H
Joosten
R
R
van Oorschot
J
J
Mos
E
E
Ronken
B
B
Olivier
D000284:Administration, Oral; D000818:Animals; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D016666:Fluvoxamine / Q000494:pharmacology*; D019004:Galanin / Q000187:drug effects / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000096:biosynthesis* / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000032:analysis; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D014660:Vasoactive Intestinal Peptide / Q000187:drug effects / Q000378:metabolism
D016666:Fluvoxamine; D019004:Galanin; D016760:Proto-Oncogene Proteins c-fos; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors; D014660:Vasoactive Intestinal Peptide