Evidence for 2D Solitary Sound Waves in a Lipid Controlled Interface and its Biological Implications

摘要

Biological membranes by virtue of their elastic properties should be capableof propagating localized perturbations analogous to sound waves. However, theexistence and the possible role of such waves in communication in biologyremains unexplored. Here we report the first observations of 2D solitaryelastic pulses in lipid interfaces, excited mechanically and detected by FRET.We demonstrate that the nonlinearity near a maximum in the susceptibility ofthe lipid monolayer results in solitary pulses that also have a threshold forexcitation. These experiments clearly demonstrate that the state of theinterface regulates the propagation of pulses both qualitatively andquantitatively. We elaborate on the striking similarity of the observedphenomenon to nerve pulse propagation and a thermodynamic basis of cellsignaling in general.