Selective deprivation of deep non-REM sleep or sleep fragmentation leads to immediate amyloid buildup in the brain in animal studies.

“the studies have now been done in humans where we will take a human being and for one single night we will take away their deep sleep and the way that you do that is that you just play these auditory tones at night so they never wake up so the total amount of sleep that they get is still eight hours but i can just selectively excise your deep sleep when that that sewage system should be kicking into gear and then the next day we do something that's really rather unpleasant we do a spinal cord puncture and we suck out some cerebrospinal fluid and we can measure the amount of the two toxic proteins linked to alzheimer's one is called beta amyloid that we've discussed the other is called tau protein and we see the next day after one night of sleep disruption a significant increase in circulating levels of amyloid and tau”

“when you take it down to the level of animal studies where they selectively deprive animals of either deep non-rem sleep or they fragment their sleep you get an immediate amyloid buildup centrally within the brain”

“After one night of essentially a loss of deep sleep, you saw an immediate rise in the amount of beta amyloid.”