Plasticity in visual cortex is disrupted in a mouse model of tauopathy

Alzheimer's disease and other dementias are thought to underlie a progressive impairment of neural plasticity. Previous work in mouse models of Alzheimer's disease shows pronounced changes in artificially-induced plasticity in hippocampus, perirhinal and prefrontal cortex. However, it is not known how degeneration disrupts intrinsic forms of brain plasticity. Here we characterised the impact of tauopathy on a simple form of intrinsic plasticity in the visual system, which allowed us to track plasticity at both long (days) and short (minutes) timescales. We studied rTg4510 transgenic mice at early stages of tauopathy (5 months) and a more advanced stage (8 months). We recorded local field potentials in the primary visual cortex while animals were repeatedly exposed to a stimulus over 9 days. We found that both short- and long-term visual plasticity were already disrupted at early stages of tauopathy, and further reduced in older animals, such that it was abolished in mice expressing mutant tau. Additionally, visually evoked behaviours were disrupted in both younger and older mice expressing mutant tau. Our results show that visual cortical plasticity and visually evoked behaviours are disrupted in the rTg4510 model of tauopathy. This simple measure of plasticity may help understand how tauopathy disrupts neural circuits, and offers a translatable platform for detection and tracking of the disease. Amalia Papanikolaou and Fabio Rodrigues et al. examine visual cortical function and intrinsic plasticity using the rTg4510 tauopathy mouse model. They demonstrate that, while basal visual cortical responses seem largely unaffected, intrinsic plasticity and the behavioural response to a visual stimulus is compromised, even in young rTg4510 mice.

Automated summary

Alzheimer's disease and other dementias impair neural plasticity. This study investigates the impact of tauopathy on visual cortical plasticity and visually evoked behaviors using a transgenic mouse model. The results reveal that both short- and long-term visual plasticity are disrupted in early stages of tauopathy and further reduced in older animals, and visually evoked behaviors are also affected.