Download Effects of Titanium Particle Radiation on the Cerebral Cortex

Effects of Titanium Particle Radiation on the Cerebral Cortex of the Mouse Brain
Stephanie Kwok
Mentor: Charles Limoli
During their missions to space, astronauts are routinely exposed to galactic cosmic radiation, which consists
of high atomic number and energy ions (HZE), such as (56) Fe, (48) Ti, and (28) Si nuclei. Using a mouse
model, we studied the effects of low dose heavy ion radiation, similar in structure and dose to the radiation
astronauts encounter in space, in the medial prefrontal cortex (mPFC), the area of the brain responsible for
executive functions such as planning, decision making, and social behavior. We analyzed the effects of oxygen
and titanium (5 and 30cGy) ion exposure on cognitive performance and a dance of morphometric parameters
in the mPFC neurons in Thy1-EGFP (6-month old) mice six weeks following irradiation. Our findings confirm that heavy ion irradiation leads to cognitive decrement in the mPFC by causing ultrastructural decrements in dendritic architecture, spine, and synaptic density. Titanium ion irradiation impaired learning and
memory responsible for discrimination between novel and familiar objects, as well as locations of objects.
Reduction in spine density exhibited a positive correlation with behavioral performance indicating radiationinduced neurodegeneration during cognitive tests.