Impairment of nesting behaviour in 3xTg-AD mice.

Deterioration in executive functions and daily life activities (DLA) are early signs of Alzheimer's disease (AD) that signal the need for caregiver attention. We have addressed this issue in the 3xTg-AD mice model for AD and studied nesting behaviour as a natural DLA of parental structures as well as at early- (6 month-old) and advanced-stages (12 month-old) of the disease in isolated animals. The results show genetic, gender and age-dependent impairment of nesting behaviour but also aware about the relevance of factors such as the temporal course of nest construction and the nesting material. Paper towel consistently showed the impairment of nesting behavior in 3xTg-AD mice since early stages of the disease and in both social conditions. Their nest construction was slow temporal pattern and of poor quality, especially in females and advanced stages of the disease where the deficits were shown from the first day. In all cases, cotton elicited an intense behaviour that lead to perfect nesting during the first 48 h. Genotype, gender and age differences were found in the onset of nesting behaviour, with a time delay in the 3xTg-AD mice, particularly in females. The reported impairment of nesting behaviour in 3xTg-AD provides another behavioral tool to assess the benefits of preventive and/or therapeutic strategies, as well as the potential action of risk factors of AD, in this animal model.