Impairment of nesting behaviour in 3xTg-AD mice. Torres-Lista Virginia,Giménez-Llort Lydia Behavioural brain research 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. 10.1016/j.bbr.2013.03.021

[Morphological analysis of the hippocampal region associated with an innate behaviour task in the transgenic mouse model (3xTg-AD) for Alzheimer disease]. Orta-Salazar E,Feria-Velasco A,Medina-Aguirre G I,Díaz-Cintra S Neurologia (Barcelona, Spain) INTRODUCTION:Different animal models for Alzheimer disease (AD) have been designed to support the hypothesis that the neurodegeneration (loss of neurons and synapses with reactive gliosis) associated with Aβ and tau deposition in these models is similar to that in the human brain. These alterations produce functional changes beginning with decreased ability to carry out daily and social life activities, memory loss, and neuropsychiatric disorders in general. Neuronal alteration plays an important role in early stages of the disease, especially in the CA1 area of hippocampus in both human and animal models. METHODS:Two groups (WT and 3xTg-AD) of 11-month-old female mice were used in a behavioural analysis (nest building) and a morphometric analysis of the CA1 region of the dorsal hippocampus. RESULTS:The 3xTg-AD mice showed a 50% reduction in nest quality associated with a significant increase in damaged neurons in the CA1 hippocampal area (26%±6%, P<.05) compared to the WT group. CONCLUSIONS:The decreased ability to carry out activities of daily living (humans) or nest building (3xTg-AD mice) is related to the neuronal alterations observed in AD. These alterations are controlled by the hippocampus. Post-mortem analyses of the human hippocampus, and the CA1 region in 3xTg-AD mice, show that these areas are associated with alterations in the deposition of Aβ and tau proteins, which start accumulating in the early stages of AD. 10.1016/j.nrl.2013.01.014