Expanding the test set: Chemicals with potential to disrupt mammalian brain development.

High-throughput test methods including molecular, cellular, and alternative species-based assays that examine critical events of normal brain development are being developed for detection of developmental neurotoxicants. As new assays are developed, a "training set" of chemicals is used to evaluate the relevance of individual assays for specific endpoints. Different training sets are necessary for each assay that would comprise a developmental neurotoxicity test battery.

A proposal to facilitate weight-of-evidence assessments: Harmonization of Neurodevelopmental Environmental Epidemiology Studies (HONEES).

The ability to conduct weight-of-evidence assessments to inform the evaluation of potential environmental neurotoxicants is limited by lack of comparability of study methods, data analysis, and reporting. There is a need to establish consensus guidelines for conducting, analyzing, and reporting neurodevelopmental environmental epidemiologic studies, while recognizing that consistency is likewise needed for epidemiology studies examining other health outcomes. This paper proposes a set of considerations to be used by the scientific community at-large as a tool for systematically evaluating the quality of proposed and/or published studies in terms of their value for weight-of-evidence assessments.

The use of developmental neurotoxicity data in pesticide risk assessments.

Following the passage of the Food Quality Protection Act, which mandated an increased focus on evaluating the potential toxicity of pesticides to children, the number of guideline developmental neurotoxicity (DNT) studies (OPPTS 870.6300) submitted to the U.S.

Determining normal variability in a developmental neurotoxicity test: a report from the ILSI Research Foundation/Risk Science Institute expert working group on neurodevelopmental endpoints.

With the implementation of the Food Quality Protection Act in 1996, more detailed evaluations of possible health effects of pesticides on developing organisms have been required. As a result, considerable developmental neurotoxicity (DNT) data have been generated on a variety of endpoints, including developmental changes in motor activity, auditory startle habituation, and various learning and memory parameters. One issue in interpreting these data is the level of variability for the measures used in these studies: excessive variability can obscure treatment-related effects, or conversely, small but statistically significant changes could be viewed as treatment related, when they might in fact be within the normal range.