Dresden 2009 – scientific programme

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BP: Fachverband Biologische Physik

BP 14: Neuronal and Sensory Systems

BP 14.10: Talk

Wednesday, March 25, 2009, 16:45–17:00, HÜL 186

Enhancement of signal detection by coupling of active hair bundles — •Kai Dierkes, Benjamin Lindner, and Frank Jülicher — Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany

In all vertebrates the hair bundle is the mechano-electrical transducer in both the auditory and the vestibular system. Hair bundles from the sacculus of the bullfrog have been shown to possess the ability to amplify weak periodic stimuli by means of an active process. In vivo hair bundles in the sacculus of the bullfrog are attached to an overlying structure that mediates a coupling between them: the otolithic membrane. The same holds true for the hair bundles of outer hair cells in the mammalian cochlea whose tips are connected to the overlying tectorial membrane. Using a stochastic description of hair bundle dynamics we have studied the effect of an elastic coupling of hair bundles. We report that collective effects in systems of coupled hair bundles can e.g. enhance the amplification gain and the sharpness of frequency tuning as compared to the performance of a single hair bundle. Our results thus suggest that coupling of hair bundles could indeed play a significant role for signal detection in inner ear organs.

Reference: Dierkes et al., 2008, PNAS 105(48),18669-18674