Different impacts on brain function depending on the mode of delivery.

The prevalence of delivery through cesarean-section (C-section) has been increasing worldwide. Although different modes of delivery, such as vaginal birth and C-section, are associated with incidence of some diseases in humans, little is known about how delivery stimuli affect short- and long-term brain function. Phenotypic analyses of Atp1a2 homozygous knockout (Atp1a2-/-) neonates showed that the mode of delivery affected neural phenotypes; Atp1a2-/- mice born by vaginal delivery started spontaneous breathing, while Atp1a2-/- mice born by C-section showed a complete absence of breathing followed by their death. This life or death phenotype prompted us to examine several aspects of the neonatal brain following C-section or vaginal delivery. We found significantly different levels of several monoamines and transporters/channel proteins and a different c-Fos expression pattern. Furthermore, these mice showed different behaviors in adulthood. Our results suggest that birth mode impacts neurotransmission and functional network formation in the neonatal brain.