Date of Award
Master of Science in Integrative Biology (MSIB)
Dr. Lisa Ganser
First Committee Member
Dr. Thomas McElroy
Second Committee Member
Dr. Troy Mutchler
Amphetamines are frequently prescribed to young children for attention deficit hyperactivity disorder (ADHD). Due to the recent rise in ADHD diagnoses and the resulting increase in amphetamine intake in children, we investigated how amphetamine exposure impacts the development of stereotyped behaviors and the neural circuit that governs these behaviors. The zebrafish (Danio rerio) was used as our model organism because of the extensively studied developmental milestones these fish provide. Using escape responses as a behavior model, we exposed embryos to three doses of amphetamine (10 μg/ml, 20 μg/ml, and 30 μg/ml) environmentally during the first 48 hours of development and used high-speed videography to identify escape behavior deficits at two time points. All doses of amphetamine exposed embryos took significantly longer to complete escape behaviors compared to controls at both time points and also displayed an increase in spastic behaviors. Also, amphetamine treated fish took significantly longer to emerge from their surrounding chorions compared to controls, which suggests developmental delays. Amphetamine fish exhibited morphological abnormalities that included tail underdevelopment, lordosis, and significantly shorter body lengths. Underlying interneural deficits are further supported with fluorescent antibody staining in the spinal cord, where inhibitory expression was significantly higher in the high amphetamine dose compared to controls. This study using 24 and 48 hpf zebrafish offers a novel perspective on early amphetamine exposure during peak developmental times. Furthermore, the combination of delayed stereotyped behaviors and morphological irregularities in this study helps provide insight to the existing literature on development and early amphetamine exposure.
Bullard, Jennifer D., "The Effects of Amphetamine Exposure on Neurodevelopment and Behavior in Early Life Stages of Danio Rerio" (2016). Master of Science in Integrative Biology Theses. 11.