Abstract

Astronauts venturing outside Earth’s magnetosphere risk exposure to charged particle radiation that has been shown to cause neurological deficits in rodents via oxidative stress, neuroinflammation, altered neurogenesis, and synaptic changes. Since these responses are similar to those observed in age-related neurodegenerative diseases, we hypothesized that individuals with a propensity toward developing Alzheimer’s disease (AD) would be more adversely affected by such exposure. To test this hypothesis, we exposed young double transgenic APP/PSEN1 mice (a commercially available strain engineered to develop AD-like neuropathology) and their wild-type (non-transgenic) counterparts to low doses of 150 MeV proton particle radiation and assessed the effects on hippocampus-dependent behaviors. Spatial learning ability, a sensitive behavioral marker of hippocampal damage, was assessed using the water maze and Barnes maze 3 and 6 months after irradiation. Transgenic mice performed worse than wild-type mice on both behavioral measures, and wild-type mice exposed to 0.5 Gy performed worse than the 0 Gy wild-type mice at 6 months post-irradiation. However, radiation doses up to 1 Gy had no effect on transgenic spatial learning performance. These findings suggest that low doses of proton radiation cause deficits in normal individuals, but may not exacerbate or accelerate learning and memory deficits in individuals predisposed toward age-related neurological disease.

LLU Discipline

Clinical Psychology

Department

Psychology

School

School of Behavioral Health

First Advisor

Hartman, Richard E.

Second Advisor

Haerich, Paul

Third Advisor

Vlkolinsky, Roman

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

2014

Date (Title Page)

9-2014

Language

English

Library of Congress/MESH Subject Headings

Alsheimer's Disease -- physiopathology; Cosmic Radiation; Protons; Central Nervous System -- Radiation effects; Neurologic Manifestations -- Radiation Effects

Subject - Local

Astronauts; Charged Particle Radiation; Oxidative Stress; Neuroinflammation; Altered Neurogenesis; Mice

Type

Thesis

Page Count

77

Digital Format

PDF

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.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

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

Download

Share

COinS