Assist. Prof. Dr. Matan Mussel (U Haifa): On spikes and sound: debating the physical nature of action potentials

Excitable cells generate a characteristic transient change in transmembrane potential that propagates along the cell membrane in response to suitable stimuli. These signals are called action potentials (APs), and are principally associated with behavioral activities of many organisms. Thus, an understanding of the mechanism of APs, as well as their actions and interactions, constitutes one of the fundamental aspects of biology. The mechanism that underlies an AP is widely considered to be electrical, and is typically interpreted through a representation of the cell membrane as an equivalent electric circuit. However, the theory relies on phenomenological equations that require many fit parameters. In addition, several experimental facts are neither readily explained nor predicted by the electrical theory. On the other hand, solitary sound pulses that propagate within lipid monolayers show remarkable similarities to APs and the theory of sound can bridge some of the gaps while using zero fit parameters. An important prediction of this approach is that electricity is merely one aspect of the signal, and it is, therefore, possible that valuable information is overlooked. The talk will conclude by proposing falsifiable predictions and discussing experimental and theoretical open questions.
Cookies, tea