PT Journal
AU Mariella Dimiccoli
   Benoît Girard
   Alain Berthoz
   Daniel Bennequin
TI Striola Magica: a functional explanation of otolith organs
SO Journal of Computational Neuroscience
JI JCN
PY 2013
BP 125
EP 154
VL 35
IS 2
DI 10.1007/s10827-013-0444-x
DE Otolith organs; Striola; Vestibular pathway
AB Otolith end organs of vertebrates sense linear accelerations of the head and gravitation. The hair cells on their epithelia are responsible for transduction. In mammals, the striola, parallel to the line where hair cells reverse their polarization, is a narrow region centered on a curve with curvature and torsion. It has been shown that the striolar region is functionally different from the rest, being involved in a phasic vestibular pathway. We propose a mathematical and computational model that explains the necessity of this amazing geometry for the striola to be able to carry out its function. Our hypothesis, related to the biophysics of the hair cells and to the physiology of their afferent neurons, is that striolar afferents collect information from several type I hair cells to detect the jerk in a large domain of acceleration directions. This predicts a mean number of two calyces for afferent neurons, as measured in rodents. The domain of acceleration directions sensed by our striolar model is compatible with the experimental results obtained on monkeys considering all afferents. Therefore, the main result of our study is that phasic and tonic vestibular afferents cover the same geometrical fields, but at different dynamical and frequency domains.
ER