目的 分析正常小型猪不同记录部位(颈部伸肌、咬肌)的前庭诱发肌源性电位(vestibular evoked myogenic potential,VEMP)波形图,并与大鼠的VEMP波形图进行比较;方法 各选取12只前庭功能正常的大鼠和小型猪,进行麻醉之后,用自制装置进行固定,1000Hz强短声诱发颈部伸肌、咬肌肌源性电位,并记录其波形;结果 大鼠颈部伸肌诱发的肌源性电位,第一个正向波P的潜伏期为6.45±0.23ms,振幅约1.45±0.49uv,80dB SPL引出率为58%;咬肌诱发肌源性电位,第一个正向波P的潜伏期为6.38±0.34ms,振幅约1.57±0.35uv,阈值80dB SPL引出率为50%。小型猪颈部伸肌诱发肌源性电位,第一个正向波P的潜伏期7.65±0.64ms,振幅1.66±0.34uv,80dBSPL的引出率为58%;咬肌诱发肌源性电位,第一个正向波P的潜伏期7.60±0.78ms,振幅1.31±0.28uv,80dBSPL的引出率为50%。结论 小型猪和大鼠不同部位记录得到的VEMP,只有振幅和引出率的差异,而潜伏期没有统计学意义;从波形的重复性、波幅的大小、引出率以及潜伏期的综合考虑,小型猪咬肌部位记录的VEMP波形优于颈部伸肌,大鼠颈部伸肌记录得到的VEMP波形优于咬肌;在相同部位记录到VEMP第一个正向P波的潜伏期时间、波幅的大小方面小型猪较大鼠的稍高。
Objective To report vestibular evoked myogenic potentials from different recording sites (neck extensor muscle and masseter muscle) in mini pigs and rats. Methods Potentials were recorded from neck extensor muscles or masse- ter muscles in normal adult Bama mini pigs and rats anesthetized with 3% pentobarbital sodium and Sumianxin II using 1000 Hz tone bursts. Results At 80 dB SPL, the latency, amplitude and response rate of the first positive wave P was 6.45± 0.23 ms, 1.45±0.49 uv and 58%, respectively, from rat neck extensor muscles; 6.38±0.34 ms, 1.57±0.35 uv and 50% from rat masseter muscles; 7.65±0.64 ms, 1.66±0.34 uv and 58% from mini pig neck extensor muscles; and 7.65±0.64 ms,.31±0.28 uv and 50% from mini pig masseter muscles. Conclusion VEMP can be recorded from neck extensor and masseter muscles in mini pigs and rats. Within a given species, VEMP amplitude and response rate are dependent on the site of recording, while latency is not. Analysis of the responses suggests that the optimal VEMP recording site is the masseter muscle in mini pigs but cervical extensor muscles in rats. At the same recording site, the latency and amplitude of VEMP are slightly greater in mini pigs than in rats.