Prenatal environmental exposures and brain development: studies with baboons and other nonhuman primates

During pregnancy, the fetal brain undergoes rapid development and is highly sensitive to environmental influences. Understanding the intricate processes that underlie fetal brain development will be critical for advancing maternal-fetal health and mitigating the risks associated with developmental brain disorders. Nonhuman primate (NHP) animal models provide a unique and highly translational platform for studying brain development during pregnancy due to the close anatomical, physiological, and behavioral resemblance of these animals to humans. Our review explores the use of NHP models in elucidating key milestones of prenatal brain maturation and the mechanisms that govern typical and atypical development. We further examine the impact of environmental insults on fetal brain development, including air pollution, infection, ionizing radiation, and exposure to toxicants, and highlight the ways in which these factors can disrupt brain development and neural circuitry, leading to long-term cognitive and behavioral deficits. Recent studies demonstrate that the baboon (Papio hamadryas) animal model provides a fruitful yet underused translational model for research related to environmental adverse effects on pregnancy. Lastly, we review the effects of drugs of abuse on the developing fetal brain, highlighting the underlying biological mechanisms identified through clinical and laboratory studies. A combined approach offers a comprehensive understanding of the vulnerabilities of the developing nervous system, informing new strategies for the treatment and prevention of neurodevelopmental disorders.