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Default daydreaming linked to Alzheimer’s amyloid

Cut the daydreaming, and you can lessen the neurodegenerative burden on your brain? Surprising new research suggests that how we use our brains may influence which parts of the brain are most vulnerable to amyloid-beta (Aβ), which forms plaques in the brain in Alzheimer’s disease.

Lary Walker, PhD, has been investigating why amyloid accumulation seems to lead to Alzheimer's in humans but not non-human primates

In the June issue of Nature Neuroscience, Yerkes National Primate Research Center scientist Lary Walker and Mathias Jucker from the Hertie Institute for Clinical Brain Research in Tübingen, Germany summarize intriguing recent research on regional brain activity and Aβ accumulation.

Neuroscientists have described a set of interconnected brain regions called the “default mode network,” which appear to be activated during activities such as introspection, memory retrieval, daydreaming and imagination. When a person engages in an externally directed task, such as reading, playing a musical instrument, or solving puzzles, activity in the default network decreases.

The Nature Neuroscience paper, from David Holtzman and colleagues at Washington University St. Louis, suggests prolonged metabolic activation of the default-mode network in mice can render that system vulnerable to Aβ by accelerating Aβ deposition and plaque growth.

This line of research turns the “use it or lose it” idea upside-down. Use the default network too much, and the effect may be harmful. Walker and Jucker suggest why education, for example, appears to head off Alzheimer’s in epidemiological studies: by getting the brain involved in non-default/externally directed mode activity.

This idea has additional consequences that can be tested in the clinic. For example, by increasing metabolism in default-mode regions of the brain, prolonged wakefulness caused by sleep disorders might increase Aβ burden.

Walker and Jucker conclude: “Meanwhile, perhaps the best strategy for lessening soluble Aβ in the default mode network may be simply to work diligently, play hard and sleep well.”


Posted on by Quinn Eastman in Neuro 2 Comments