Uri Nevo (Tel Aviv University) | Thoughts on the mechanics of our thoughts |
Brain activity is a set of electrical events, setting the basis for the view of the brain as a unique binary-coded electric computer. However, neuronal activity includes multiple mechanical events. The propagating wave of depolarization includes release of heat and a wave of swelling that acts like an acoustic wave along the interface of the lipid bi-layer. Both phenomena have no place in the classical Hodgkin-Huxley model. What is the biological origin of these and of additional mechanical events? What is their physiological importance?
In this lecture I will propose a new hypothesis regarding the way mechanical changes in active neurons define the phenomenon of short term memory. Specifically, we suggest that action potentials trigger an in-flow and release of Ca2+ to the cell’s cytosol. We suggest that this inflow triggers the recruitment of Myosin light chains on the cellular circumference and their phosphorylation. This may happen on a very fast time scale and increase tension that persists in activated neurons. Thus, activated neuronal circuits become a preferred route for further mechanical activations. We suggest that this is the known ‘activity-silent’ short term memory: a state-shift of the activated cells that become more susceptible to further activations relative to other cells. This view suggests that the brain is not different from other tissues that employ mechano-electric pulses to create forces and lead to actions. The potential implications extend beyond basic brain research, to the practical study of aging, neurodegenerative diseases and other brain pathologies.
When: February 7, 2024 2:00 PM (Israel Standard Time).
Where: Room 223, Multipurpose Bldg. & over Zoom