• Environmental Agent Exposure and Stress during Development

    We are investigating the effects of manganese (Mn) in combination with stress when exposure occurs during early development. This is an important area of investigation in children’s health since Mn exposure occurs in young children from soy-based infant formulas, ferromanganese industrial plants, and well water in areas with naturally occurring ground water Mn. In addition, Mn exposure is seen more often in low social economic status (SES) families.

    Low SES conditions have been associated with stress, and children in these situations tend to have higher levels of circulating cortisol.

    We are investigating the effects of Mn and stressors as models of low SES on the development of monoamine neurotransmitters in the brain, hormonal responses to stress, and behavior, especially learning and memory.

    We find that early exposure to Mn leads to long-term changes in neurotransmitters, especially dopamine, and to spatial and egocentric learning and memory deficits. Chronic stress has similar effects. We are currently investigating the mechanisms of these effects and how these factors interact. We are also investigating if early Mn exposure leads to increased susceptibility of Parkinson’s disease.