Journal of Clinical Toxicology
Open Access
ISSN: 2161-0495
+44 1478 350008
ISSN: 2161-0495
+44 1478 350008
Daniel N Weber
Scientific Tracks Abstracts: J Clinic Toxicol
T he physico-biological context within which organisms live defines the quality and quantity of behavioral responses. This is especially true in toxicity tests using behavioral endpoints. Using a series of behavioral outcomes (e.g., startle responses, agonistic interactions, locomotor activity, and learning),we explored 5 sources of variation in behavioral toxicity tests: genotype, circadian rhythms, exposure age, social interactions and environmental enrichment. 1) Contaminants affect gene expression. Genetic mechanisms also affect toxic outcomes. We observed that zebrafish homozygous for a congenital cardiovascular defect learned with greater difficulty vs. heterozygous individuals or wild types. Additionally, lead (Pb 2+ )-exposed female zebrafish displayed greater agonistic activity than males. 2) We examined circadian locomotor activity rhythms of Pb 2+ -exposed fish. Single time-of-day testing yielded a different picture of toxic responses than did a full examination of the entire 24-hr cycle 3) We demonstrated age-sensitivity in a learning test for zebrafish; 1-year-old adults were less affected by methylmercury exposure than 2-year-old fish. 4) Animals live in a social context that affects behavior. We demonstrated that Pb 2+ -exposed fish responded differently to the presence of other non-exposed fish vs. their general activity level in the absence of other fish and their group behavior when all the fish are exposed was altered. 5) Enriched environments can mitigate contaminant-induced behavioral deficits. We demonstrated that spatially enriched environments can reverse previously observed increases in agonistic activity among Pb 2+ -exposed zebrafish. These factors need to be considered when designing behavioral toxicity experiments.
Daniel Weber received his PhD from the University of Wisconsin-Milwaukee in Ethology and Physiology. He is currently a Senior Scientist at the UW-Milwaukee Children?s Environmental Health Sciences Center where he is the Manager of the Neurobehavioral Toxicology Facility. As part of the Center?s community outreach and engagement core, Dr. Weber is instrumental in developing high school.