Sex differences in vestibular effects of magnetic fields

描述(申请人提供)：磁共振成像(MRI)的进步正在推动具有4-9特斯拉(T)的静态磁场(MFS)的MRI机器的发展；然而，人们对高强度MFS在哺乳动物或人类身上产生的感觉或生理效应知之甚少。最近，我们的实验室证明，暴露于高强度MFS会对雄性大鼠和小鼠的行为和神经产生影响。在行为学上，暴露于MF可引起循环和条件性味觉厌恶(CTA)。在这些行为中存在性别和发情周期的差异，表明对MF的行为反应依赖于卵巢类固醇。在神经水平上，暴露可诱导脑干内脏核团和前庭核团c-Fos的表达。这些影响类似于前庭紊乱的影响，如旋转。我们假设暴露于MF会激活大鼠的前庭器官，并且对暴露于MF的反应存在性别差异，从而使雌性大鼠表现出更强的转圈和更持久的CTA。因此，我计划使用c-Fos，一种与行为类似的神经反应，并使用LCM和RT-PCR来证明前庭系统中类固醇受体的存在。这些实验将有助于理解这些效应背后的神经通路。此外，这些实验可能有助于预测高强度核磁共振对人类的影响。

DESCRIPTION (provided by applicant): Advances in magnetic resonance imaging (MRI) are driving the development of MRI machines with static magnetic fields (MFs) of 4 - 9 tesla (T); however, little is known about the sensory or physiological effects high strength MFs produce in mammals or humans. Recently, our lab demonstrated that exposure to high strength MFs produces behavioral and neural effects in male rats and mice. Behaviorally, MF exposure induced circling and conditioned taste aversion (CTA). There are sex and estrous cycle differences in these behaviors suggesting that the behavioral response to MF is dependent upon ovarian steroids. At the neural level, MF exposure induced c-Fos in brainstem visceral and vestibular nuclei. These effects are similar to the effects of vestibular disturbance, such as rotation. We hypothesize that MF exposure activates the rat's vestibular apparatus and that there is a sex difference in the response to MF exposure such that females show enhanced circling and more persistent CTA. Therefore, I plan to demonstrate, using c-Fos, a neural response that parallels behavior, and using LCM and RT-PCR, the presence of steroid receptors in the vestibular system. These experiments will contribute to the understanding of the neural pathways underlying these effects. In addition, these experiments may help predict the effects of high-strength MRI on humans.