Department of Psychology
Master of Arts
Smoking continues to be a significant health problem in the United States and throughout the world. One of the many aspects of the health risks of smoking that have been investigated is the effect of maternal smoking on developing embryos. In particular, exposure of embryos to nicotine is believed to cause attention-deficit/hyperactivity disorder (ADHD) and related problems in children. Both correlational research with humans and experimental research with animals have supported this belief. However, the mechanisms of the effect of nicotine on developing embryos are not fully understood. The zebrafish offers a useful model of the effects of nicotine on developing organisms because its development is fast, well understood, and easily observable. Also, the embryo can be exposed to nicotine without concern for many of the intermediate factors that are present in research with conventional models (e.g., the rat), such as the effect of nicotine on the placenta. This study was an exploratory attempt to establish the zebrafish as a model for the effects of embryonic nicotine (EN) exposure. Zebrafish eggs were exposed to two levels of nicotine during the first eight hours after fertilization. These subjects and a group of controls were measured on three variables at different stages of development: body length, activity level, and avoidance learning. Results showed that EN exposure caused a significant decrease in growth and a significant increase in activity level. Thus, the zebrafish responds to EN exposure in a manner similar to that observed in other models and in humans. Further research on the mechanisms of the effect of EN exposure may be possible using the zebrafish.
Lawrence, Tim, "Body Length, Activity Level, and Avoidance Learning in Zebrafish Exposed to Nicotine as Embryos" (2001). Masters Theses & Specialist Projects. Paper 673.