Graduation Year

2017

Document Type

Dissertation

Degree

Ph.D.

Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Medical Sciences

Major Professor

R. Douglas Shytle, Ph.D.

Co-Major Professor

Paula C. Bickford, Ph.D.

Committee Member

Edwin Weeber, Ph.D.

Committee Member

Thomas Taylor-Clark, Ph.D.

Committee Member

Brian Giunta, Ph.D.

Keywords

Acetaminophen, BTBR T+Itpr/tf (BTBR), Excitatory amino acid transporter 3 (EAAT3), Glutathione (GSH), Autism spectrum disorder (ASD)

Abstract

Autism is a lifelong neurodevelopmental disorder. The etiology of autism still remains unclear due to the heterogeneous and complex nature of the disorder, however synergistic actions between genetic components and environmental factors have been suggested. Acetaminophen (APAP) is one of the most popular over-the-counter drugs that possess antipyretic and analgesic effects. It is considered a relatively safe and effective within therapeutic doses. Recently, early exposure to APAP has been suggested to be one of the underlying cause of autism. Children are often prescribed APAP to lessen fever or irritability after vaccination during the first year, and APAP may adversely affect the normal brain development. In order to better understand the association with APAP and autism, we used an inbred mouse strain BTBR T+tf/J (BTBR). BTBR exhibits behavioral deficits that mimic the core behavioral deficits of human autism. In the study, investigated 1) if BTBR mice showed differences in thiol biochemistry and EAAT3 levels in brain compared with C57BL/6J (C57) mice, 2) if early exposure to APAP induced behavioral changes worsening the autistic phenotypes of BTBR in adolescence, and 3) if APAP exposure in neonatal mice induced possible toxicity at various doses. As a result, we observed that BTBR mice have significantly lower plasma sulfate levels and EAAT expression levels in the frontal cortex compared to C57 mice. Surprisingly, neonatal therapeutic dose of APAP administration did not induce behavioral changes in both C57 and BTBR in adolescence. However, we showed that a supratheraputic dose of APAP significantly elevated levels of oxidative stress marker in the brain. Overall, the results suggested that BTBR mice would be a useful mouse model to investigate effects of various environmental factors that have been associated with autism. In addition, early exposure to APAP at supratherapeutic doses may negatively affect normal brain development.

Available for download on Friday, May 11, 2018

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