Repeated closed-head traumatic brain injury (rTBI) can result in serious consequences, such as the development of neurodegenerative diseases like Alzheimer’s Disease (AD), chronic traumatic encephalopathy (CTE), and many others. This study characterizes the consequences of injury timing in a Drosophila melanogaster model of rTBI. Specifically, each fly was subjected to 4 strikes with a modified “high impact trauma” (HIT) device. The strikes were separated by either 5 minutes, 2 hours, 4 hours, or 36 hours. These inter-strike intervals theoretically provided an opportunity to study outcomes of repeated brain injury during times of unresolved rTBI mechanisms. Half of the flies were raised on diets supplemented with polyphenols to determine whether this would ameliorate the consequences of rTBI. A series of behavioral tests (climbing abilities, locomotor activity) was administered after the last strike, and the age at which each fly died was recorded. The results demonstrated that traumatic brain injury (TBI) reduced post-injury survival and climbing abilities, a pomegranate juice diet protected against 24-hour mortality, and an ellagic acid + sugar diet shortened lifespan. Regarding inter-injury intervals, 240-minute inter-injury interval flies had an improved lifespan, 2160-minute inter-injury interval flies had the lowest climbing performance, and female flies subjected to the 2160-minute inter-injury protocol had a reduced 24-hour mortality. This study helped to elucidate rTBI consequences by using a fruit fly model of TBI that allowed for subsequent injury during literature-derived windows of primary and secondary TBI injury mechanisms. Research continuing to build on this focus of injury intervals is important for strengthening empirical support for the conceptualization and treatment of the many individuals that sustain a TBI.

LLU Discipline





School of Behavioral Health

First Advisor

Richard Hartman

Second Advisor

David Vermeersch

Third Advisor

Grace Lee

Fourth Advisor

Travis Fogel

Degree Name

Doctor of Philosophy (PhD)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Drosophila melanogaster; Brain Injuries, Traumatic


Doctoral Project

Page Count

xii, 70 p.

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives

Included in

Psychology Commons