The release of neurotransmitter from a vestibular hair cell into the synapse with a sensory neuron would increase
A) in response to any mechanical stimulation of the hair cell.
B) when the stereocilia of the hair cell are displaced away from the kinocilium.
C) when the stereocilia are equally displaced to either side of the kinocilium.
D) when the stereocilia of the hair cell are displaced toward the kinocilium.

Question

Quizplus · Accepted Answer

The stereocilia of vestibular hair cells are arranged in a V-shape, with the tallest stereocilia closest to the kinocilium (the central stereocilium). When the head moves, these stereocilia are displaced either towards or away from the kinocilium, which causes the hair cell to depolarize or hyperpolarize, respectively. The release of neurotransmitter from the hair cell into the synapse with a sensory neuron occurs when the hair cell depolarizes, which happens when the stereocilia of the hair cell are displaced towards the kinocilium. Therefore, the correct answer is D.

The Release of Neurotransmitter from a Vestibular Hair Cell into the Synapse