The glymphatic system clears metabolic waste in the brain by exchanging the interstitial fluid (ISF) surrounding neurons with ‘clean’ cerebrospinal fluid (CSF). Two new studies show that neurons drive glymphatic clearance of waste, including pathogenic proteins such as amyloid. Noninvasive gamma sensory stimulation, which has already entered clinical trials for the treatment of Alzheimer disease (AD), was found to promote the clearance of amyloid via this mechanism.

Li-Feng Jiang-Xie and colleagues investigated the relationship between neuronal oscillations during sleep and glymphatic waste clearance. “Given that sleep problems and waste accumulation are frequently intertwined with neurodegenerative diseases, we hypothesized that exploring these two fundamental processes may shed some light on the pathophysiology of neurological disorders, such as AD,” explains Jiang-Xie.