Postnatal fluoxetine treatment affects the development of serotonergic neurons in rats.
The goal of the present study was to investigate morphological changes in the serotonergic neurons/terminals in the dorsal (DR) and median (MnR) raphe nuclei and on the hippocampal dentate gyrus (DG) in neonatal rats treated from the 1st to the 21st postnatal day with fluoxetine (10 mg/kg sc, daily) or drug vehicle (0.9% saline 1 ml/kg). The results show that postnatal chronic treatment with fluoxetine promoted: (1) a smaller body weight increase during the pre-weaning period; (2) smaller number of 5-HT neurons in the DR; (3) smaller 5-HT neuronal cell bodies (area, perimeter and diameter) in the DR and the MnR and (4) diminished serotonergic terminals in the DG. These data suggest that the development of the serotonergic system was impaired and that early exposure to fluoxetine damaged the morphology of 5-HT neurons in young adult rats. While these findings are consistent with other work, more studies are needed to better clarify the effects of postnatal chronic treatment with fluoxetine on the serotonergic system and, consequently, on the functions modulated by serotonin.
Silva
Cristiano Mendes da
CM
Department of Biosciences, Federal University of Sao Paulo/UNIFESP (Campus Baixada Santista), 11060-001 Santos, Brazil. cristiano.mendes@unifesp.br
Gonçalves
Luciano
L
Manhaes-de-Castro
Raul
R
Nogueira
Maria Inês
MI
D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight / Q000187:drug effects; D018891:Dentate Gyrus / Q000166:cytology / Q000254:growth & development; D005473:Fluoxetine / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D011903:Raphe Nuclei / Q000166:cytology / Q000254:growth & development; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*
D005473:Fluoxetine; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors