Long-term dynamics of aberrant neuronal activity in Alzheimer’s disease

Alzheimer’s disease (AD) is associated with aberrant neuronal activity levels. How those activity alterations emerge and how stable they are over time , however, remains elusive to date. To address these questions we chronically recorded the activity from identified neurons in cortex of awake APPPS1 transgenic mice and their non-transgenic littermates over the course of 4 weeks by means of calcium imaging. Surprisingly, aberrant neuronal activity was very stable over time. Moreover, we identified a slow progressive gain of activity of former intermediately active neurons as the main source of new highly active neurons. Interestingly, fluctuations in neuronal activity were independent from amyloid plaque proximity, but aberrant activity levels were more likely to persist close to plaques. These results support the notion that neuronal network pathology observed in AD patients is the consequence of stable single cell aberrant neuronal activity, a finding of potential therapeutic relevance.