Authors

Sarah Ponce

Date

Spring 2020

Faculty Advisor

Dr. Laura Dyer

College/School

College of Arts & Sciences

Department

Biology

Abstract

Fetal alcohol syndrome (FAS) occurs in 0.2 to 1.5 per 1,000 infants born. FAS results in symptoms such as abnormal craniofacial features, impaired cognitive abilities and cardiovascular defects. However, the impact of prenatal ethanol exposure on the neural crest cells responsible for cardiac innervation remains understudied. This study investigates the effect of variable timing of ethanol treatment on cardiac and trunk neural crest cells and the subsequent impact on cardiac innervation. Early ethanol treatment led to decreased apoptosis in the neural tube and increased apoptosis in the migratory pathway towards the outflow tract in the cardiac neural crest. Early ethanol exposure also decreased cardiac neural crest cell migration in the cardiac circumpharyngeal ridge and increased neural crest cell migration in the pharyngeal arches. Later ethanol exposure resulted in increased apoptosis in the trunk neural crest region of the neural tube and decreased neuronal branching on the anterior base of the outflow tract. Later ethanol exposure also substantially increased migration in the circumpharyngeal ridge in the trunk neural crest and slightly increased migration in the cardiac neural crest region of the circumpharyngeal ridge. These findings suggest that early ethanol exposure may lead to a lack of selection for the proper neural crest cells reaching the heart necessary for survival, and that later alcohol treatment shows a similar impairment in the selection process for neural crest arriving to the heart, resulting in reduced cardiac neuron branching. Further studies can determine how cardiac innervation is influenced by varying concentrations of neural crest arriving to the heart and how apoptosis shapes the directionality and specification of the migratory pathway.

Subjects

Fetal alcohol spectrum disorders; Heart--Innervation

Publication Information

Copyright for this work is retained by the author.

BIO493H: Senior Honor's Project

Document Type

Student Project

Available for download on Thursday, November 03, 2022

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