Cupula and endolymph dynamics
Watch endolymph flow and cupula deflection in both lateral canals during head rotation. Bar displays show the push-pull change in vestibular nerve firing rate.
Head turn:
0°/s
What's happening
At rest, both vestibular nerves fire at their resting tonic rate (~90 Hz). The cupula sits undeflected in the ampulla. This baseline symmetry is what the brain interprets as "no head motion."