Figure 2.

Resting discharge pattern and response to stimulation of an irregular and a regular afferent. (A) Time series of an irregular otolith neuron during stimulation by 500 Hz bone-conducted vibration (BCV) and air-conducted sound (ACS). The top trace (a) shows the command voltage, indicating when the stimulus is on. The second trace shows the action potentials by extracellular recording. The three bottom traces (x, y, z) show the triaxial accelerometer recording of the stimulus. The left panel is an example of response to BCV stimulation and the right of the response to ACS stimulation of the same neuron, showing it is clearly activated by both stimulus types. Note the scale of stimulus intensity in g at the left margin between traces x and y. The irregular resting discharge is seen before stimulus onset, followed by a large increase in firing during both BCV and ACS. (B) Time series of a regular semicircular canal neuron during stimulation by BCV and ACS as above. The regular discharge is seen before the stimulus onset. The stimuli are far stronger than in panel (A), but there is no evidence of activation of this regular neuron by these strong stimuli. From Ref. (19), Curthoys and Vulovic, © Springer-Verlag, 2010, reproduced with permission of Springer.