Epidemiological and case study reports in children have provided compelling evidence for significant neurobehavioral deficits associated with elevated environmental and dietary manganese (Mn) exposure. However, these studies have not established a causal relationship between Mn exposure and neurobehavioral deficits, nor have they provided a detailed understanding of the specific nature of the cognitive deficits (i.e., learning, attention, emotionality, etc.), or underlying neurochemical alterations.
Aim 1 will determine whether pre-weaning or continuous postnatal Mn exposure produces neurobehavioral deficits in young adults, using a rodent model of Mn neurotoxicity.
Aim II will explore the molecular and neurochemical mechanisms underlying the cognitive deficits induced by pre-weaning or continuous postnatal Mn exposure.
Aim III will determine the relationship of pre-weaning or continuous postnatal Mn exposures with biological markers of exposure, and the extent that these exposure biomarkers are associated with neurobehavioral and neurochemical alterations. We will test the overarching hypotheses that (1) neonatal Mn exposure causes lasting dysfunction in various aspects of cognitive (i.e., learning, memory, attention and/or inhibitory control) and affective (arousal and/or emotion) functioning, and (2) that these changes are linked to developmental alterations in dopaminergic and glutamatergic systems in brain regions which subserve these functions (i.e., the prefrontal cortex, striatum, and hippocampus). We will measure cellular and neurochemical parameters of dopaminergic and glutamatergic system function by microdialysis/biosensor, receptor binding, and immunohistochemistry in the same animals that underwent cognitive testing, in order to provide information about Mn-induced changes in systems that subserve these behavioral functions, and to determine whether one or more of these neural changes correlate with behavioral deficits. Further, we will directly test whether alteration of the dopaminergic system due to Mn exposure plays a role in the resulting behavioral deficits by determining whether Mn exposure alters the dose- response relationship of methylphenidate (Ritalin), a dopamine transporter (DAT) inhibitor, and whether the drug alleviates behavioral deficits due to Mn exposure. These studies will be the most comprehensive assessments to date on the neurological consequences of early life exposure to levels of manganese that infants and children are likely to encounter in their environment. This knowledge will inform public health policies and guidelines on suitable levels of Mn exposure to children.
The proposed studies will address a significant gap in our understanding of the health risks posed by elevated manganese exposure in children by defining in detail the link between early life or continuous postnatal manganese exposure and lasting cognitive deficits, the neurochemical alterations underlying those deficits, and biomarkers that best predict exposure and effects, using a rodent model of childhood Mn exposure. These studies will be the most comprehensive assessments to date on the neurological consequences of early life exposure to levels of manganese that infants and children are likely to encounter in their environment. This knowledge will inform public health policies and guidelines on suitable levels of Mn exposure to children.
|Beaudin, Stephane A; Strupp, Barbara J; Uribe, Walter et al. (2017) Methylphenidate alleviates manganese-induced impulsivity but not distractibility. Neurotoxicol Teratol 61:17-28|
|Bauer, Julia Anglen; Claus Henn, Birgit; Austin, Christine et al. (2017) Manganese in teeth and neurobehavior: Sex-specific windows of susceptibility. Environ Int 108:299-308|
|Chiu, Yueh-Hsiu Mathilda; Claus Henn, Birgit; Hsu, Hsiao-Hsien Leon et al. (2017) Sex differences in sensitivity to prenatal and early childhood manganese exposure on neuromotor function in adolescents. Environ Res 159:458-465|
|Austin, Christine; Richardson, Cardius; Smith, Donald et al. (2017) Tooth manganese as a biomarker of exposure and body burden in rats. Environ Res 155:373-379|
|Beaudin, Stephane A; Strupp, Barbara J; Strawderman, Myla et al. (2017) Early Postnatal Manganese Exposure Causes Lasting Impairment of Selective and Focused Attention and Arousal Regulation in Adult Rats. Environ Health Perspect 125:230-237|
|Beaudin, Stéphane A; Strupp, Barbara J; Lasley, Stephen M et al. (2015) Oral methylphenidate alleviates the fine motor dysfunction caused by chronic postnatal manganese exposure in adult rats. Toxicol Sci 144:318-27|
|Mora, Ana M; Arora, Manish; Harley, Kim G et al. (2015) Prenatal and postnatal manganese teeth levels and neurodevelopment at 7, 9, and 10.5 years in the CHAMACOS cohort. Environ Int 84:39-54|
|Lucas, E L; Bertrand, P; Guazzetti, S et al. (2015) Impact of ferromanganese alloy plants on household dust manganese levels: implications for childhood exposure. Environ Res 138:279-90|
|Mora, Ana M; van Wendel de Joode, Berna; Mergler, Donna et al. (2015) Maternal blood and hair manganese concentrations, fetal growth, and length of gestation in the ISA cohort in Costa Rica. Environ Res 136:47-56|
|Mora, Ana M; van Wendel de Joode, Berna; Mergler, Donna et al. (2014) Blood and hair manganese concentrations in pregnant women from the infants' environmental health study (ISA) in Costa Rica. Environ Sci Technol 48:3467-76|
Showing the most recent 10 out of 23 publications