Age-related neurodegeneration is characterized by rising levels of various protein aggregates in the brain. A few of the many thousands of proteins in the body can become misfolded in ways that encourage other molecules of the same protein to also misfold in the same way, forming structures that spread and precipitate into solid deposits. These aggregates are accompanied by a halo of surrounding biochemistry that is toxic to neurons, disrupting function in the brain and killing vital cells, causing loss of cognitive function and ultimately death.

In recent years, increasing attention has been given to the role of cerebrospinal fluid drainage in maintaining the brain. The circulation of cerebrospinal fluid is not a closed system, but one that drains into the body via a few different routes. This is a path for molecular waste of all sorts to be removed from brain tissue, but unfortunately it deteriorates with age. The company Leucadia Therapeutics is founded on evidence for one such drainage path, through the cribriform plate, to become blocked with age, thereby leading to the early stages of Alzheimer's disease because amyloid-β cannot be cleared as rapidly as is needed. Similarly, other paths through the glymphatic system also deteriorate with age, for different reasons, and with similar consequences for the clearance of molecular waste.

Today's open access paper is of interest in this broader context. It examines one of the mechanisms by which waste can be packaged up into granules, exported from brain tissue into the cerebrospinal fluid, and thereby drained from the brain to be dealt with by immune cells elsewhere in the body.

Corpora amylacea act as containers that remove waste products from the brain