Impact of Cesarean Delivery on Reward Behavior and Tyrosine Hydroxylase in the Nucleus Accumbens of Adult Prairie Vole Offspring.

Birth by cesarean section (CS) is associated with a higher incidence of dopamine (DA)-related disorders compared to vaginal delivery (VD). The mesolimbic (ML) system encompasses DAergic neurons that modulate processes underlying learning, motivation, and food intake. Previous work has found lower levels of DA in the prefrontal cortex and higher levels in the nucleus accumbens (NAc) of CS offspring. Since alterations in the ML-DA system after CS birth may impact behavioral response to rewarding stimuli, we aimed to ascertain the behavioral and neurodevelopmental outcomes relevant to food reward in CS prairie vole offspring. This study utilized conditioned place preference (CPP) testing to assess learning, operant conditioning to assess motivation to receive a reinforcer, and immunohistochemistry (IHC) to stain for tyrosine hydroxylase (TH) in the NAc. Behavioral results showed no difference in preference for the conditioned chamber between CS offspring and their VD counterparts. CS prairie vole offspring had a lower average breakpoint during progressive ratio testing compared to VD offspring. IHC results showed CS offspring had lower levels of TH-immunoreactivity in the NAc core and shell. These findings further support that delivery by CS has long-term neurodevelopmental effects and that CS offspring have decreased food motivation independent of deficits in learning.