Connection of brain glymphatic system with circadian rhythm

To establish a relationship between the glymphatic system of brain and circadian rhythm, we analyzed the effect of anomalies in water thermodynamics on dependence of dynamic, electrical, and optical characteristics of physiological fluids on temperature. The dynamics of hydrogen bonds in bulk and hydrated water affected the activation energies of ion currents of voltage-dependent channels that regulate signaling and trophic bonds in neuropil of the cortical parenchyma. The physics of minimizing of isobaric heat capacity of water made it possible to explain stabilization and functional optimization of thermodynamics of eyeball fluids at 34.5 °C and human brain during sleep at 36.5 °C. At these temperatures, thermoreceptors of cornea and cells of ganglionic layer of the retina, through connections with suprachiasmatic nucleus and pineal gland, switch circadian rhythm from daytime to nighttime. The phylogenesis of circadian rhythm was reflected in dependence of duration of nighttime sleep of mammals on diameter of eyeball, mass of pineal gland, and density of neurons in parenchyma of cortex. The activity of all nerves of eyeball led to division of night sleep into slow and fast phases. In the first phase, there are relaxation processes of synaptic plasticity and in the second - increase water exchange in parenchyma and flush out toxins into the venous system. Electrophysics of clearance and conductivity of ionic and water channels of membranes of blood vessels and astrocytes modulate oscillations of polarization potentials of water dipole domains in parietal plasma layers of arterioles and capillaries.