172 | The impact of early fluoxetine exposure on serotonin content and neuronal activity after memory tasks in adult mice.


Author: Karen Melany Stefani | Email: karen.stefani.1995@gmail.com

Karen Stefani , Rocío Foltran , Alba Vieites Prado , Patricia Gaspar , Nicolas Renier , Silvina Diaz

1° Instituto de Biología Celular y Neurociencia ” Prof. E. De Robertis” (IBCN), CONICET – Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
2° Intitut du Cerveau, Hôpital de la Pitié-Salpêtrière, Paris, France

Perinatal exposure to antidepressants (ADs) may have long term consequences in affective behaviors during childhood. This have been also well characterized in adult mice after postnatal exposition to ADs. Nevertheless, the impact of this kind of exposition on memory tasks, adult neurogenesis as well as brain 5-HT levels has been less explored. Therefore, we orally treated male and female C57BL/6 mice, from postnatal day 2 (P2) to P14 with the AD fluoxetine (10 mg/kg) or vehicle. Survival of newborn neurons in the hippocampus (HC) of adult mice was analyzed through EdU and BrdU labeling, showing a significant decrease of neurons in mice that have received fluoxetine. Whereas 5-HT levels were significantly lower in the HC of Flx-treated mice at P15, brain levels were similar to controls in adult mice. In addition, mice that received Flx assayed in the memory object recognition test and the object pattern separation had a significantly worse performance than control animals. Expression of the immediate early gene c-fos in the dorsal HC was increased by the AD treatment. All in all, our results show that early exposition to Flx in mice affects the development of newborn neurons in the HC with lasting consequences on memory abilities as well as in dorsal hippocampal expression of c-fos after memory tasks.