title: Evidence for two-dimensional solitary sound waves in a lipid controlled interface and its implications for biological signalling.
abstract: Biological membranes by virtue of their elastic properties should be capable of propagating localized perturbations analogous to sound waves. However, the existence and the possible role of such waves in communication in biology remain unexplored. Here, we report the first observations of two-dimensional solitary elastic pulses in lipid interfaces, excited mechanically and detected by FRET. We demonstrate that the nonlinearity near a maximum in the susceptibility of the lipid monolayer results in solitary pulses that also have a threshold for excitation. These experiments clearly demonstrate that the state of the interface regulates the propagation of pulses both qualitatively and quantitatively. Finally, we elaborate on the striking similarity of the observed phenomenon to nerve pulse propagation and a thermodynamic basis of cell signalling in general.
authors.affiliation: Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
authors.forename: Shamit
authors.initials: S
authors.lastname: Shrivastava
authors.affiliation: Department of Mechanical Engineering, Boston University, Boston, MA 02215, USA mfs@bu.edu.
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Schneider
mesh_terms: D003198:Computer Simulation; D008051:Lipid Bilayers / Q000737:chemistry*; D040542:Mechanotransduction, Cellular; D008560:Membrane Fluidity; D008567:Membranes, Artificial; D008956:Models, Chemical; D009038:Motion; D013016:Sound; D013314:Stress, Mechanical; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D008567:Membranes, Artificial; D014867:Water
keywords: action potential; lipid monolayer; non-equilibrium thermodynamics; nonlinear acoustics; signalling; solitary sound waves