Stimulus and recording variables and their effects on mammalian vestibular evoked potentials.
Linear vestibular evoked potentials (VsEPs) measure the collective neural activity of the gravity receptor organs in the inner ear that respond to linear acceleration transients. The present study examined the effects of electrode placement, analog filtering, stimulus polarity and stimulus rate on linear VsEP thresholds, latencies and amplitudes recorded from mice. Two electrode-recording montages were evaluated, rostral (forebrain) to 'mastoid' and caudal (cerebellum) to 'mastoid'. VsEP thresholds and peak latencies were identical between the two recording sites; however, peak amplitudes were larger for the caudal recording montage. VsEPs were also affected by filtering. Results suggest optimum high pass filter cutoff at 100-300 Hz, and low pass filter cutoff at 10,000 Hz. To evaluate stimulus rate, linear jerk pulses were presented at 9.2, 16, 25, 40 and 80 Hz. At 80 Hz, mean latencies were longer (0.350-0.450 ms) and mean amplitudes reduced (0.8-1.8 microV) for all response peaks. In 50% of animals, late peaks (P3, N3) disappeared at 80 Hz. The results offer options for VsEP recording protocols.
Department of Surgery, Division of Otolaryngology, University of Missouri School of Medicine, Rm 205 Allton Bldg., DC375.00, 301 Business Loop 70W, Columbia, MO 65212, USA. jonessh@health.missouri.edu
Sherri M
SM
Jones
Geetha
G
Subramanian
Wilma
W
Avniel
Yuqing
Y
Guo
Robert F
RF
Burkard
Timothy A
TA
Jones
D000818:Animals; D004594:Electrophysiology / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D014724:Vestibular Function Tests / Q000379:methods*; D014722:Vestibule, Labyrinth / Q000502:physiology*
NASA Discipline Neuroscience; Non-NASA Center