Walter Bradford Cannon, a former Chairman of the Department of Physiology at Harvard Medical School (1906-1942), developed the concepts of ‘homeostasis’ (stability of the inner world); the ‘Fight or Flight Response’, and The ‘Sympathoadrenal System’. In 1932, Cannon published The Wisdom of the Body, where he popularized the new term of the dynamic equilibrium/steady state of the internal milieu or homeostasis.
The ‘glymphatic system’, recently discovered by professor Maiken Nedergaard and her group,is the system that drains waste products from the brain. The cerebrospinal fluid moves through the brain along a series of channels that surround blood vessels. The system is managed by the brain’s glial cells, and so the researchers called it the glymphatic system (see image at the right hand side).
How does the brain dispose of its interstitial fluid? How is brain waste eliminated? How are these processes relevant for dementia and neurodegeneration? These are a few questions discussed by Drs. Ferretti and Iulita in their BrainImmune’s article. The authors outline recent finding published in Science magazine, related to fluid dynamics in the brain in health and disease. The glymphatic system is mostly active during sleep. Yet the glymphatic system degrades with age, suggesting a causal relationship between sleep disturbance and symptomatic progression in the neurodegenerative dementias.
These findings provide a thorough description of the key mechanisms governing the brain’s glymphatic system, and the role of sleep in promoting fluid flow and brain waste elimination. Importantly, it appears that that a dysfunction of such mechanisms is a key, common basis to many neurodegenerative diseases involving protein aggregation, including Alzheimer’s disease, Parkinson’s and tau-related dementias.
One reason is that the topic, or factual search term “the discovery of interferon”, linked and related to the above-mentioned BrainImmune article – over the last 5-6 years – always shows up on the first page of a Google search! Perhaps another reason is that during the second year of the pandemic, the interest towards interferons is increased, as interferon deficit and issues have been linked to the pathogenesis of COVID-19.