Molecular Imaging: The New Frontier in Neurotoxicology

The use of molecular imaging techniques in neurotoxicology research is currently lacking. There are a small number of case reports and long-term epidemiological studies in which modalities such as magnetic resonance imaging (MRI) are used to assess the effect of neurotoxicant exposure on brain volume or magnetic resonance spectroscopy (MRS) is used to examine the effect of heavy metal exposure on brain metabolites. Despite these efforts, the application of other neuroimaging modalities such as positron emission tomography (PET) in neurotoxicology has been limited in both clinical studies and experimental animals. However, it is known that a large percentage of neurotoxicant-induced neurological impairments are mediated through alterations of neurotransmitter systems that are amenable for studies using PET and single photon emission computed tomography (SPECT). In this chapter, the feasibility and value of using these powerful state-of-the-art neuroimaging modalities to assess neurotoxicant-induced changes in brain chemistry will be described. Molecular imaging of the brain holds tremendous promise for neurotoxicological research in the understanding of molecular mechanism and for risk assessment.