静态高磁场(MF)与人类和啮齿动物的前庭系统相互作用。在大鼠和小鼠中,暴露于MF会导致头部运动等扰动,圆形运动,压制饲养,眼球震颤,和条件性的味觉厌恶获取。为了测试耳石的作用,检查了两个突变小鼠模型:头倾斜Nox3het(het)和倾斜Opt1tlt(tlt),分别在Nox3中具有突变,编码NADPH氧化酶3酶,和Opt1,编码opterin1质子通道,通常在耳石器官中表达,对耳石形成至关重要。因此,两种突变体在囊和囊中都显示出接近完全的耳胶损失,并且对线性加速度无响应。将小鼠暴露于14.1TMF30分钟。暴露后,运动活动,评估了条件味觉厌恶和c-Fos(在het中)。暴露于MF的野生型小鼠表现出抑制的饲养,增加了向后的延迟,运动盘旋,和与前庭处理相关的脑干核中的c-Fos(prepositus,脊柱前庭,和上音核)。突变het小鼠对磁体没有反应,并且在所有测定中与假动物相似。不像Het,与假对照相比,暴露于MF的tlt突变体显示出明显的运动循环和抑制的饲养,尽管他们没有获得品味厌恶。tlt与het小鼠的残余反应性可能反映了het小鼠更大的半圆形缺陷。这些结果证明了耳石对暴露于高MF的全部影响的必要性,但也暗示了半圆形的贡献。
Static high magnetic fields (MFs) interact with the vestibular system of humans and rodents. In rats and mice, exposure to MFs causes perturbations such as head movements, circular locomotion, suppressed rearing, nystagmus, and conditioned taste aversion acquisition. To test the role of otoconia, two mutant mouse models were examined, head-tilt Nox3het (het) and tilted Otop1 (tlt), with mutations, respectively, in Nox3, encoding the NADPH oxidase 3 enzyme, and Otop1, encoding the otopetrin 1 proton channel, which are normally expressed in the otolith organs, and are critical for otoconia formation. Consequently, both mutants show a near complete loss of otoconia in the
utricle and saccule, and are nonresponsive to linear acceleration. Mice were exposed to a 14.1 Tesla MF for 30 min. After exposure, locomotor activity, conditioned taste aversion and c-Fos (in het) were assessed. Wild-type mice exposed to the MF showed suppressed rearing, increased latency to rear, locomotor circling, and c-Fos in brainstem nuclei related to vestibular processing (prepositus, spinal vestibular, and supragenual nuclei). Mutant het mice showed no response to the magnet and were similar to sham animals in all assays. Unlike het, tlt mutants exposed to the MF showed significant locomotor circling and suppressed rearing compared with sham controls, although they failed to acquire a taste aversion. The residual responsiveness of tlt versus het mice might reflect a greater semicircular deficit in het mice. These results demonstrate the necessity of the otoconia for the full effect of exposure to high MFs, but also suggest a semicircular contribution.