Effects of neonatal alcohol exposure and an adolescent exercise intervention on myelin basic protein density in a rodent model of FASD
Date
2022
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
Fetal Alcohol Spectrum Disorders, or FASD, is an umbrella term that encompasses the disorders resulting from prenatal alcohol exposure. The resulting neurological, cognitive, and behavioral deficits range from mild to severe and include disruptions in executive functioning such as variations in attention, memory, and problem solving. An important neuroanatomical structure for overall interhemispheric communications, and specifically for executive function, is the corpus callosum (CC), the largest white matter tract in the brain which connects the two hemispheres. Previous research in humans, as well as in animal models has shown that developmental alcohol exposure can cause structural alterations to the CC, including decreased volume and disrupted myelination. Since aerobic exercise has been shown to be a stimulator of myelin plasticity, we investigate the use of a voluntary exercise intervention and its effect on the development of the corpus callosum. This study uses a rodent model of a third trimester binge alcohol exposure and immunohistochemistry to examine if third-trimester alcohol-induced changes to the corpus callosum structure last through adolescence and to determine if an aerobic exercise intervention can ameliorate alcohol-induced damage to CC. ☐ Two cohorts of animals were used in this study: one with tissue collected at early adolescence (PD 30) and one in late adolescence (PD 45). CC in both control and alcohol-exposed female rats at PD 30 had significantly higher density of myelin basic protein (MBP), a biomarker for myelin in the brain, than in CC of male rats. Additionally, neonatal alcohol exposure increased female MBP expression and lowered male MBP in the caudal subregion of the CC specifically. At the late adolescent time point, no main effects were found, but pairwise comparisons implicated that neonatal alcohol exposure (AE) increased the sedentary female rat’s MBP density, and that AE female rats were the most positively affected by the adolescent exercise intervention, which lowered the density of MBP to control levels. Finally, the MBP density was increased by voluntary exercise in the caudal subregion of the AE male rats. These findings detail some ways in which the effects of developmental AE (animal model of third-trimester alcohol exposure) and exercise on the adolescent brain are sexually dimorphic, and encourage further research into exercise as a positive effector in the stimulation of myelin plasticity.
Description
Keywords
Adolescence, Alcohol exposure, Development, Exercise, FASD, Myelination