Special Seminar by Assoc Professor Michele Bellesi

Sleep Loss and Myelin Homeostasis: Implications for Brain Function and Behavior

You are warmly invited to a special seminar by Michele Bellesi, MD, PhD, Associate Professor at the School of Biosciences and Veterinary Medicine, University of Camerino, Italy, who will give a lecture titled:

“Sleep Loss and Myelin Homeostasis: Implications for Brain Function and Behavior”

When: Thursday, September 17th, 2026, at 15.00-16.00

Where: ZOOM

Host: Professor Iiris Hovatta

Short abstract:

Sleep loss impairs cognitive and motor performance, yet the underlying biological mechanisms remain incompletely understood. Most studies have emphasized neuronal and synaptic alterations, leaving the contribution of glial cells and white matter comparatively unexplored. In this seminar, I will present evidence that chronic sleep loss disrupts oligodendrocyte function and myelin integrity, leading to delayed neural signal propagation in vivo. Integrating human diffusion MRI analyses with molecular, ultrastructural, electrophysiological, and behavioral approaches in animal models, we show that sleep loss reduces white matter integrity, induces myelin thinning, and increases interhemispheric conduction delays.
At the cellular level, sleep loss alters cholesterol homeostasis in oligodendrocytes and increases membrane fluidity, thereby compromising myelin-dependent conduction velocity. Enhancing cholesterol redistribution to myelin prevents conduction delays and rescues behavioral impairments despite ongoing sleep restriction.
Together, these findings identify oligodendrocytes and myelin as key mediators of reduced behavioral performance following sleep loss and suggest that sleep supports efficient neuronal communication by maintaining myelin integrity.