Date of Award
Master of Science
Previous studies have analyzed causal factors among infants who succumb to Sudden Infant Death Syndrome (SIDS). Two causal factors include the presence of a brain abnormality and exogenous stressors, it was hypothesized that cerebellar Purkinje cell (PC) dysfunction would inhibit ventilation during graduated challenges of isocapnic hypoxia conditions (19%, 17%, 15%, and 13% O2/ 3% CO2) compared to normal room air (21% O2, 0% CO2, 79% N). The challenges of isocapnic hypoxia conditions were chosen to simulate an environment with exogenous stressors that an infant with an unknown brain abnormality might experience. Experiments were carried out on sibling pairs of a mouse model of Duchenne’s muscular dystrophy (C57BL/10ScSn-Dmdmdx/J). Minute ventilation, comprised of tidal volume and breath frequency, was measured using whole body plethysmography during baseline exposure to normal room air and to isocapnic hypoxia conditions between both groups at post-natal day 62 (n = 7 for both wildtype and DMD mdx mutant). Groups did not show a significant difference in ventilatory responses during isocapnic hypoxia conditions compared to baseline. The combination of the dual gas challenge could have the effect of both decreasing and increasing ventilation responses simultaneously. Future research should focus on a single challenge of hypoxia or hypercapnia or chronic exposure to hypoxia or hypercapnia to explore the possibility of revealing respiratory responses much differently than those exposed to acute isocapnic hypoxia.
dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.
Longest, Katherine R., "Cerebellar Abnormalities in Developing DMD Mdx Mice and Respiratory Compensatory Responses to Acute Isocapnic Hypoxia" (2017). Electronic Theses and Dissertations. 1656.