Otolith Geometry


Utricle.mat (901 kB): "Utricle" is a structure, containing the {x / y / z}-data of the left utricle, in [mm]. The z-component of the utricle is eleveated by 0.05 mm with respect to the surrounding, and "indx" contains the locations of the edge. For technical reasons, the first and last column contains the slice number (or so ...). The coordinate system is described below.

Saccule.mat (811 kB): same as above, but with the structure "Saccule".


To determine hair cell polarization vectors across the epithelium, we specified the curved surfaces of the utricular and saccular epithelia. They were obtained from the measurements of Takagi et al. of human labyrinths (Takagi et al., 1988). The original data set contained the geometrical locations, organized in rows that corresponded to slices of the maculae. This data set was pre-processed to remove artefacts of slicing. Single misplaced rows were shifted or deleted to create smooth surfaces. Additional points in the periphery of the measured data points were introduced which helped to smoothly extend the macular surface beyond the original data set. The subsequent use of this geometrical data required the representation of the surfaces on a regular grid. A standard interpolation scheme was employed for this purpose. Remaining artefacts of the slicing procedure were removed by smoothing the data set with a Savitzky-Golay filter. Filter settings ensured that only artefacts were removed.
The geometrical data were represented with respect to a coordinate system that allowed simple comparison with existing observations. We employed the same system as used by Goldberg et al. (1976). In this coordinate system, the x-axis points out the left ear, the y-axis out of the back of the head and the z-axis out of its top. Since the original data set also included the semi-circular canals, it was possible to use their orientation together with the measured orientation of the semi-circular canals (Blanks et al. 1975) to adjust the data set by a sequence of rotations.
Regions that represent measured data points are elevated. The insets illustrate the orientation of the coordinate system.


Blanks RHI, Curthoys IS, Markham CH (1975) Planar relationships of the semicircular canals in man Acta Otolaryngol 80: 156-196

Fernandez C, Goldberg JM (1976a) Physiology of peripheral neurons innervating otolith organs of the squirrel monkey. I. Response to static tilts and to long-duration centrifugal force J Neurophysiol 39: 970-984

Takagi A, Sando I (1988) Computer-aided three-dimensional reconstruction and measurement of the vestibular end-organs Otolaryngol Head Neck Surg 98: 195-202

created by T Haslwanter, last changed 8-March-2004