The goal of this study was to determine the effect of changes in core body temperature on the resting discharge rate and sensitivity of vestibular-nerve afferents. Extracellular recordings were made from vestibular-nerve afferents innervating the semicircular canals in anesthetized C57BL/6 mice maintained at a core body temperature of either 30 – 32° (T31) or 35 – 37° (T36) C. The resting rates of regular (CV* < 0.1) and irregular afferents (CV* > 0.1) were lower at T31 than at T36. Sensitivity and phase were compared for rotations ranging from 0.1 – 12 Hz by calculating coefficients of a transfer function, g·tc1s·(tzs + 1)/(tc1s + 1), for each afferent. The sensitivity (g) increased with CV* and with higher core body temperature. The value of the coefficient representing the low-frequency dynamics (tc1) varied inversely with CV* but did not change with core body temperature. The high-frequency dynamics represented by tz increased with CV* and decreased with higher core body temperature. These findings indicate that changes in temperature have effects on the static and dynamic properties of vestibular-nerve afferents.
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