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Criteria for selection of reference chemicals for the evaluation of alternative methods to assess developmental neurotoxicity

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©Alexandr Vasilyev - Fotolia.com
Jan 24 2017

In collaboration with international organisations, a JRC scientist defined criteria for the selection of positive/negative control samples to assess developmental neurotoxicity hazard posed by environmental and industrial chemicals.

The assessment of chemicals for potential developmental neurotoxicity (DNT) effects is almost entirely based on animal tests. However, the standard tests (e.g. OECD Test Guideline 426) are rarely performed since they are seldom requested by regulators and are very time-consuming and costly to conduct. As a result, there is a lack of information concerning the potential DNT hazard posed by chemicals to which workers and consumers may be exposed.
This lack of effective and efficient testing approaches and DNT information is of concern since there is growing evidence of possible links between the exposure of children to chemicals and developmental learning disabilities. Moreover, it is well known that the developing nervous system in children is more sensitive than the adult nervous system for some classes of hazardous substances.
New testing approaches based on batteries of in vitro tests offer new non-animal test systems to screen chemicals for potential DNT effects. The first generation of alternative DNT methods are based on evaluation of fundamental neurodevelopmental processes including neuronal differentiation, precursor cell migration and neuronal network formation since any alternations of these processes may result in DNT effects.
To aid in the development and performance evaluation of these new in vitro approaches, JRC scientists have worked with other experts in the field to establish a directory of over 100 reference chemicals. This reference directory and the supporting guidance on its use provide an invaluable resource to method developers and end-users to more systematically and comprehensively assess the reliability and predictivity of test batteries in order to demonstrate their utility to support safety decisions in a regulatory context.

Read more in:
M. Aschner et al. "Reference compounds for alternative test methods to indicate developmental neurotoxicity (DNT) potential of chemicals: example lists and criteria for their selection and use", ALTEX 34 (2017) 49-74  doi: 10.14573/altex.1604201