Dopamine D1 receptor changes due to caesarean section birth: effects of anesthesia, developmental time course, and...

There is an epidemiological association between increased obstetric complications and disorders involving CNS dopamine dysregulation, such as schizophrenia. In light of this, a rat model of global hypoxia during Caesarean section (C-section) birth has been used to directly test if birth complications can produce long-term dopaminergic dysregulation. Previous studies have shown that, compared to vaginal birth, C-section birth alone (without additional global hypoxia) is sufficient to increase D1-like receptor binding in rat brain at adulthood. The current study examined (1) the developmental time course of changes in D1-like or D2-like receptors following C-section birth; (2) whether C-section birth from isoflurane-anesthetized dams also results in altered D1-like receptor levels, as does C-section from decapitated dams; and (3) behavioral responses to D1 and D2 agonists in rats born vaginally compared to C-section. Increases in nucleus accumbens D1-like receptor binding due to C-section birth were observed only at adulthood (3 months) but not prepubertally (1 month or 2 weeks). D2-like receptor binding levels were unaffected by C-section birth across the three developmental time points. Compared to vaginal birth, D1-like receptors were increased following C-section birth from isoflurane-anesthetized dams, as well as from decapitated dams. Adult rats that had been born by C-section showed enhanced D1 potentiation of D2-induced locomotor behavior. These studies indicate that C-section birth, from either anesthetized or unanesthetized dams, results in postpubertal increases in D1-like receptor binding and enhanced functional responses to D1 receptor activation.