Class Year




Document Type


Distinguished Thesis


Degree Name

Bachelor of Arts (BA)

Department or Program


First Advisor

Douglas B. Light

Second Advisor

Matthew R. Kelley

Third Advisor

Benjamin E. Zeller

Fourth Advisor

Daniel A. Peterson, Rosalind Frankln University of Medicine and Science


In the past few decades, the rate of traumatic brain injuries (TBI), particularly concussions from sports or combat, has nearly doubled. TBI is thought to increase the likelihood of neurodegenerative diseases, such as chronic traumatic encephalopathy. The sequence of degenerative and regenerative responses underlying these disorders has been unclear and was the focus of this study. We utilized a closed-head model of the controlled cortical impactor to deliver injury to rats. Our results indicate a progressive increase in ventricular size and a corresponding progressive decrease in hippocampal, cortical, and corpus callosal volume. Stereological estimates indicate neuronal cell loss in region CA1 of the hippocampus, which progressed with time. Additionally, we identified an astrocytic response but neither a response from microglia nor oligodendrocyte progenitor cells. Overall, we characterized the subtle pathological changes that occur following repeat, mild traumatic brain injury using a clinically relevant model of concussions.