Effects of serotonergic manipulation in the brainstem and hypothalamus of overnourished rats during lactation.

Previous studies suggest that being overweight and obese is capable of altering brain function during critical periods due to the higher plasticity of the brain during development. However, more literature still needs to be on the immediate effect of overnutrition and serotonin modulation in brain areas. In this study, we aimed to evaluate the effects of serotoninergic manipulation on oxidative stress and pro-inflammatory markers in the brainstem and hypothalamus of overnourished rats. The fluoxetine treatment was performed from postnatal day 3 (PND3) to postnatal day 21 (PND21) to evaluate mitochondrial function, oxidative balance, and the mRNA levels of monoaminergic molecules such as serotonin and dopamine, pro-inflammatory cytokines, and BDNF. Neonatal overnutrition induces molecular and biochemical changes in the brainstem and hypothalamus. These nutritional disturbances during lactation dysregulate energy balance and cellular redox, inducing oxidative stress. Conversely, modulation of the serotoninergic system through pharmacological use of fluoxetine was able to reverse the deleterious effects of overnutrition during lactation, enabling better brain development and delaying the development of pathologies and oxidative stress.