Non-invasive sound stimulation altered Alzheimer’s-linked proteins in aged monkeys in a recent study, with effects lasting more than five weeks.
Alzheimer’s involves abnormal amyloid proteins that form plaques and damage synapses, the junctions between nerve cells.
Cerebrospinal fluid is the liquid that bathes the brain and spinal cord.
In a study of nine rhesus macaques aged 26 to 31, animals received one hour of 40Hz auditory stimulation daily for seven days.
Researchers at the Chinese Academy of Sciences reported a sharp rise in amyloid levels in the cerebrospinal fluid after treatment, consistent with proteins being cleared from the brain.
Levels remained elevated five weeks after stimulation ended.
The researchers wrote: “Seven days’ stimulation triggered a rapid CSF Aβ increase by more than 200 per cent.
“This study provides the first primate evidence that 40Hz auditory stimulation can sustainably modulate the Aβ metabolism in the brain, supporting its potential as a non-invasive AD treatment method.”
The team said the approach could be developed as a non-invasive, low-cost physical intervention compared with antibody drugs used in early disease, though clinical testing in people will be needed to confirm benefit.