Myelin: A possible proton capacitor for energy storage during sleep and energy supply during wakefulness

• Published in: Progress in biophysics and molecular biology Vol. 196; pp. 91 - 101
• Main Authors: Morelli, Alessandro Maria, Saada, Ann, Scholkmann, Felix
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2025
• Subjects: Adenosine Triphosphate - metabolism; Animals; Brain - metabolism; Energy Metabolism; Humans; Mitochondria - metabolism; Mitochondrial derived vesicles; Myelin; Myelin Sheath - metabolism; Oxidative Phosphorylation; Proton capacitor; Protons; Sleep; Sleep - physiology; Wakefulness - physiology; Mitochondrial derived vesicles; Sleep; Proton capacitor; Myelin
• ISSN: 0079-6107; 1873-1732; 1873-1732
• DOI: 10.1016/j.pbiomolbio.2025.03.001

There are several physiological reasons why biological organisms sleep. One key one concerns brain metabolism. In our article we discuss the role of metabolism in myelin, based on the recent discovery that myelin contains mitochondrial components that enable the production of adenosine triphosphate (ATP) via oxidative phosphorylation (OXPHOS). These mitochondrial components in myelin probably originate from vesiculation of the mitochondrial membranes in form from mitochondrial derived vesicles (MDVs). We hypothesize that myelin acts as a proton capacitor, accumulating energy in the form of protons during sleep and converting it to ATP via OXPHOS during wakefulness. Empirical evidence supporting our hypothesis is discussed, including data on myelin metabolic activity, MDVs, and allometric scaling between white matter volume and sleep duration in mammals. •A new hypothesis as to why living organisms need sleep•Sleep: accumulation of protons in the myelin•Wakefulness: discharge of the myelin proton capacitor and production of ATP