J.Comparat.Physiol.A 193(4), 445-459, 2007
B. Hößl¹², H.J. Böhm¹,
F.G. Rammerstorfer¹, F.G. Barth²
¹Institute of Lightweight Design and Structural
TU Wien, Vienna, Austria
²Life Sciences, Department for Neurobiology and Behavioral Sciences,
University of Vienna, Vienna, Austria
Arachnid strain sensitive slit sensilla are elongated openings in the cuticle
with aspect ratios (slit length l / slit width b) of up to 100.
Planar Finite Element (FE) models are used to calculate the relative slit face
displacements, D(c), at the centers of single slits and of arrangements
of mechanically interacting slits under uni-axial compressive far-field loads.
Our main objective is to quantitatively study the role of the following
geometrical parameters in stimulus transformation: aspect ratio, slit shape,
geometry of the slits' centerlines, load direction, lateral distance S,
longitudinal shift λ, and difference in slit length Δl
between neighboring slits.
Slit face displacements are primarily sensitive to slit length and load
direction but little affected by aspect ratios between 20 and 100.
In stacks of five parallel slits at lateral distances typical of lyriform
organs (S=0.03l) the longitudinal shift lambda substantially
influences slit compression.
A change of λ from 0 to 0.85 l causes changes of up to 420% in
D(c). Even minor morphological variations in the arrangements can
substantially influence the stimulus transformation.
The site of transduction in real slit sensilla does not always coincide with
the position of maximum slit compression predicted by simplified models.