Figure 3.

A, Vestibular responses of three IN neurons sensitive to sinusoidal WBR (2 Hz, ±10°/s) or side-to-side WBT (2 Hz, ± 0.05 G). Each row corresponds to a different type of unit including a canal-only unit that responded only during WBR and not during side-to-side WBT, an otolith-only unit that responded during side-to-side WBT but not during WBR, and a canal–otolith unit that responded during both WBR and side-to-side WBT. Traces shown include: head velocity (Ḣ), head acceleration (Ḧ), and unit discharge rate (gray fill). Schematic illustrations shown above each figure correspond to the paradigm that was used. Fits for estimating vestibular sensitivities are shown superimposed on the unit's discharge rate (see Materials and Methods). All recordings were from animal B. All averages included 30 stimulus cycles. All three of these example neurons also have neck sensitivity and are discussed in later figures. B, Polar plots summarizing the vestibular response properties of IN neurons. Left, Gain and phase response properties of IN neurons during 2 Hz WBR for canal-only (n = 14) and canal–otolith (n = 23) neurons. Type I (right-hand plane, filled symbols) and type II (left-hand plane, open symbols) are shown. Gains and phases were computed with respect to rotational velocity. Right, Gain and phase response properties of IN neurons during 2 Hz EVA-WBR as a function of unit type (otolith-only, n = 7; canal–otolith, n = 23). Gains and phases were computed with respect to translational acceleration.