What happens when stereocilia bend toward or away from a kinocilium?

In the vestibular system of the inner ear, the movement of stereocilia relative to the kinocilium is a critical mechanism for sensing head orientation and movement.1

When stereocilia bend toward the kinocilium, ion channels in the hair cell membrane open. This allows potassium ions to flow into the cell, resulting in depolarization. Conversely, when movement causes the stereocilia to bend away from the kinocilium, these ion channels close, preventing the influx of potassium ions and resulting in hyperpolarization.1

These polarization changes trigger associated neurons to send electrical impulses to the brain, providing essential information for balance and the stabilization of vision.1