New research conducted at Washington University in St Louis suggests that removing the orexin protein in mice enables them to sleep longer, which could serve to hinder development of the disease.
One of the ways that the orexin protein and sleep loss can lead to Alzheimer's is through enabling the development of brain plaques. These build up before and during the onset of Alzheimer's and correlate with the development of symptoms like memory loss and disorientation, leading scientists to believe that halting their buildup may go some way to combating the disease.
Putting this theory to the test, the researchers used mice that were genetically engineered to possess elevated amyloid beta, the protein that helps to make up brain plaques. By breeding these mice with other mice lacking the orexin protein, the researchers found the offspring had less sleep problems and developed around half as many plaques.
Mice with no orexin slept for around an hour extra during twelve-hour observation periods, while mice with orexin were more lively. Conversely, when the researchers heightened orexin levels, the mice stayed awake for longer and grew more plaques. Another noteworthy finding was that manipulating orexin levels in a section of the brain unrelated to the mouse's ability to sleep had no bearing on levels of plaque.