Wednesday, February 26, 2014

Such a waste of perfectly good fruit flies

Scientists wake up to causes of sleep disruption in Alzheimer's disease
People with Alzheimer's often have poor biological rhythms, something that is a burden for both patients and their carers. Periods of sleep become shorter and more fragmented, resulting in periods of wakefulness at night and snoozing during the day. They can also become restless and agitated in the late afternoon and early evening, something known as 'sundowning'.

...They found that healthy flies were active during the day and slept at night, whereas those with Alzheimer's sleep and wake randomly. Crucially, however, the diurnal patterns of the luciferase-tagged protein were the same in both healthy and diseased flies, showing that the biological clock still ticks in flies with Alzheimer's.
"Until now, the prevailing view was that Alzheimer's destroyed the biological clock," said Crowther.
"What we have shown in flies with Alzheimer's is that the clock is still ticking but is being ignored by other parts of the brain and body that govern behaviour. If we can understand this, it could help us develop new therapies to tackle sleep disturbances in people with Alzheimer's."

Um, how about this?
The hypocretin system is affected in advanced AD. This is reflected in a 40% decreased cell number, and 14% lower CSF hypocretin-1 levels.
That might explain some of the insulin problems too, huh?