Characterization of the 3xTg-AD mouse model of Alzheimer's disease: part 2. Behavioral and cognitive changes.

Alzheimer's disease (AD) is characterized by distinct behavioral and cognitive deficits that differ from those observed in normal aging. Transgenic models of AD are a promising tool in understanding the underlying mechanisms and cause of disease. The triple-transgenic mouse model of AD (3xTg-AD) is the only model to exhibit both Abeta and tau pathology that is characteristic of the human form. The present study characterized the performance of 3xTg-AD mice on several tasks measuring behavioral and cognitive ability. Aged 3xTg-AD females exhibited a higher level of fear and anxiety demonstrated by increased restlessness, startle responses, and freezing behaviors. No differences were observed in muscle strength and visuo-motor coordination. Understanding the behavioral manifestations that occur in this model of AD may aid in the early diagnosis and appropriate treatment of AD symptomology.