Abstract:
Alzheimer’s disease (AD) is a neurodegenerative disease that affects cognition, behavior,
and function. AD is considered a growing health concern because the number of patients
with AD doubles every five years after age 65. AD is characterized by two types of
lesions in the brain: intraneuronal neurofibrillary tangles and extracellular neuritic
(senile) amyloid plaques--the plaques are an accumulation of β-amyloid (Aβ). There is
considerable evidence suggesting that metals play a critical role in aggregating Aβ into
neuritic plaques. Studies examining the role of metals in formulating Aβ plaque
complexes have produced varying results. Further investigation into the role of metals in
plaque formation might help uncover possible treatment interventions. The current study
examines brain tissue from the Tg2576 transgenic mice model. The Tg2576 model is
considered a staple in AD-related studies, and it is the most widely used model of AD in
the world. In the current study, Tg2576 mice were split into groups and administered lab
water, 10ppm zinc (Zn) water, 10ppm iron (Fe) water, or 10ppm zinc and copper (Cu)
water. In AD, amyloid plaque congregation has been studied throughout the brain,
including in transition cortex, piriform cortex, hippocampus, neocortex, amygdala nuclei,
and basal ganglia. These brain regions are most commonly associated with learning and
memory. Plaque-containing brain tissue from each of these regions was analyzed in
Tg2576 mice using BioQuant. Plaque burden was assessed using three measurement
parameters: normalized area, average area, and plaque number. Results showed that
overall plaque burden was highest in the brains of animals raised on Zn and Zn + Cu
water and highest in the cortical areas (transition & piriform cortex followed by
neocortex). Plaque burden was less in the brains of mice raised on Fe water and less in
the basal ganglia. The effects of metal type and brain region appeared to be independent.
