Mechanical Characteristics of Rat Vibrissae: Resonant Frequencies and Damping in Isolated Whiskers and in the Awake Behaving Animal

• DOI: 10.1523/jneurosci.23-16-06510.2003
• Publication Date: 2018-04-13T22:30:28Z
• Authors: Mitra J. Hartmann; Nicholas J. Johnson; R. Blythe Towal; Christopher Assad
• Keywords: Behavior, Animal; Biophysics; Video Recording; Organ Size; Models, Biological; Vibration; Rats; Rats, Sprague-Dawley; Motion; 03 medical and health sciences; 0302 clinical medicine; Biological Clocks; Touch; Vibrissae; Exploratory Behavior; Animals; Female; Trigeminal Nerve; Wakefulness

We investigated the natural resonance properties and damping characteristics of rat macrovibrissae (whiskers). Isolated whiskers rigidly fixed at base showed first-mode peaks between 27 260 Hz, principally depending on whisker length. These experimentally measured resonant frequencies were matched using a theoretical model as conical cantilever beam, with Young's modulus only free parameter. The best estimate for was ∼3-4 GPa. Results both vibration impulse experiments that are strongly damped, ratios 0.11 0.17. In behaving animal, deflected past an object observed to resonate but damped significantly more than isolated whiskers. time course varied individual phase whisking cycle, which suggests may modulate biomechanical parameters affect damping. No resonances did not contact or during in air. Finally, same side face sometimes move opposite directions over full duration whisk. discuss potential roles exploratory behavior specifically suggest oscillations be important rat's tactile detection boundaries.