Sex differences in vestibular effects of magnetic fields

描述（由申请人提供）：磁共振成像（MRI）的进步正在推动具有4 - 9特斯拉（T）静磁场（MF）的MRI机器的发展;然而，对高强度MF在哺乳动物或人类中产生的感觉或生理效应知之甚少。最近，我们的实验室证明，暴露于高强度的MF会对雄性大鼠和小鼠产生行为和神经影响。行为上，MF暴露诱导盘旋和条件性味觉厌恶（CTA）。这些行为存在性别和发情周期差异，提示对MF的行为反应依赖于卵巢类固醇激素。在神经水平，MF暴露诱导脑干内脏核和前庭核的c-Fos。这些效应类似于前庭干扰的效应，例如旋转。我们假设，MF暴露激活大鼠的前庭器官，并且对MF暴露的反应存在性别差异，例如女性表现出增强的盘旋和更持久的CTA。因此，我计划证明，使用c-Fos，一个神经反应，平行的行为，并使用LCM和RT-PCR，类固醇受体在前庭系统的存在。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MRI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.