How to keep up with the analysis of classic and emerging neurotoxins: Age-resolved fitness tests in the animal model - a step-by-step protocol.

The global chemical inventory includes neurotoxins that are mostly interrogated concerning the biological response in developing organisms. Effects of pollutants on adults receive less attention, although vulnerabilities can be expected throughout the entire life span in young, middle-aged and old individuals. We use the animal model to systematically quantify neurological outcomes by application of an age-resolved method. Adult hermaphrodite worms were exposed to pollutants or non-chemical stressors such as temperature in liquid culture on microtiter plates and locomotion fitness was analyzed in a whole-life approach. Cultivation at 15, 20 or 25 °C showed that worms held at 15 °C displayed an enhanced level of fitness concerning swimming movements until middle age (11-days-old) and then a decline. In contrast, cultivated at ≥ 20 °C continually reduced their swimming movements with increasing age. Here, we provide a step-by-step protocol to investigate the health span of adult that may serve as a platform for automation and data collection. Consistent with this, more neurotoxins can be investigated with respect to vulnerable age-groups as well as contributing non-chemical environmental factors such as temperature.