Motor deficits in 16-month-old male and female 3xTg-AD mice

• Published in: Behavioural brain research 2019-01, Vol.356, p.305-313
• Main Authors: Garvock-de Montbrun, Thalia, Fertan, Emre, Stover, Kurt, Brown, Richard E.
• Format: Article
• Language: English
• Subjects: 3xTg-AD; Age Factors; Aging; Alzheimer Disease - genetics; Alzheimer’s disease; Amyloid beta-Peptides - metabolism; Animals; Behavior, Animal - physiology; Disease Models, Animal; Female; Gait - physiology; Hippocampus - metabolism; Male; Mice, Transgenic; Motor Activity - physiology; Motor behaviour; Mouse model; Plaque, Amyloid - genetics; Plaque, Amyloid - metabolism; Sex Characteristics
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2018.09.006

•At 6 months of age, 3xTg mice performed better on motor tests than WT mice.•On the Rotarod, 16 month old 3xTg mice showed better performance than WT mice.•On the balance beam, 16 month old 3xTg mice showed worse performance than WT mice.•There were no significant genotype or sex differences in other motor tests.•Domains of motor function are affected differently in the 3xTg mice as they age. Motor deficits are some of the most prevalent non-cognitive symptoms of Alzheimer’s disease (AD) with patients showing impairments in speech, gait and fine motor skills. We investigated motor behaviour in 16-month-old male and female 3xTg-AD mice and their B6129SF2 wildtype (WT) controls. The 3xTg-AD mice develop extracellular Aβ plaques and tau tangles in the hippocampus and motor cortex between 6 and 9 months of age. Previously we showed that at 6 months of age, 3xTg-AD mice performed better on tests of motor coordination and motor learning than WT mice. The aim of our experiment was to use a battery of motor behaviour tests to determine if this superior motor performance was present in older mice. On the Rotarod, the aged 3xTg-AD mice showed better motor coordination and learning than WT mice. Although females performed better than males, this sex difference was confounded by body weight as females weighed less than males. There were no significant genotype or sex differences on the wire hang or grid suspension tasks, nor in stride length or stride width, but 3xTg-AD mice performed worse than WT mice on the balance beam. In comparison to the 6-month-old mice, an age-related decline in most aspects of motor behaviour was apparent. These results indicate that different sub-domains of motor function are affected differently in the 3xTg-AD mice and that aging does not have the same effect on all motor behaviours.