SGER: Characterization of the Magnetic Compass in C57 BL/6 Mice

磁罗盘的特征是C57 BL/6 MiceJohn B。Phillips生物系Virginia Tech Blacksburg，VA 24061- 0406项目摘要。这项拟议中的研究将使用实验室小鼠的行为方法来研究负责检测地球磁场的感觉机制。 实验室小鼠的C57 BL/6品系将被用于研究是否有一类新发现的色素参与同步昼夜节律的光暗周期（隐花色素），这也涉及磁场感应，是小鼠的磁罗盘的重要组成部分。 还将进行实验，以确定低水平、宽带（1-20 MHz）无线电频率场是否会破坏磁罗盘定向（如最近对鸟类和两栖动物的研究所示）。对于一个给定的频率（7 MHz）显示影响鸟类的磁罗盘方向，强度阈值的影响磁罗盘方向的鼠标系统将被确定。这项工作的潜在影响包括：（1）表征小型哺乳动物对磁场敏感的机制;（2）表征在新感觉系统进化过程中发生的分子变化（磁罗盘）从一个特征鲜明的先行词（光依赖性生物钟）;（三）开发生物物理和遗传技术，用于操纵对磁信息的访问，这些磁信息可用于研究磁刺激在其他疾病中的作用。行为和神经生理反应;（4）与美国和国外的一些实验室合作开发研究项目，目标是：a）使用离散的无线电频率来表征作为磁罗盘基础的生物物理过程，B）对光敏生物钟中的变化进行建模，所述变化对于优化对小，光输入的磁场依赖性调制，以及c）识别涉及磁信息处理的大脑区域。

Characterization of the Magnetic Compass is C57 BL/6 MiceJohn B. PhillipsBiology DepartmentVirginia TechBlacksburg, VA 24061-0406Project Summary. The proposed research will use a behavioral approach with laboratory mice to investigate the sensory mechanism responsible for detection of the Earth's magnetic field. The C57 BL/6 strain of laboratory mouse will be used to investigate whether a newly-discovered class of photopigments involved in synchronizing circadian rhythms to the light-dark cycle (cryptochromes), which have also been implicated in magnetic field sensing, are an essential component of the mouse's magnetic compass. Experiments will also be carried out to determine whether low-level, broad band (1-20 MHz) radio frequency fields disrupt magnetic compass orientation (as shown in recent studies of birds and amphibians). For a given frequency (7 MHz) shown to affect magnetic compass orientation of birds, the intensity threshold for an effect on magnetic compass orientation in the mouse system will be determined. The potential impact of this work includes: (1) characterization of the mechanism responsible for magnetic field sensitivity in a small mammal; (2) characterization of the molecular changes that have occurred during the evolution of a novel sensory system (the magnetic compass) from a well-characterized antecedent (the light-dependent circadian clock); (3) development of biophysical and genetic techniques for manipulating access to magnetic information that can be used to investigate the role of magnetic stimuli in other behavioral and neurophysiological responses; (4) development of collaborative research programs with a number of laboratories in the USA and abroad with the goals of: a) using discrete radio frequencies to characterize the biophysical processes underlying the magnetic compass, b) modeling the changes in a light-sensitive circadian clock that would be necessary to optimize sensitivity to small, magnetic-field-dependent modulations of light input, and c) identifying brain regions involved in the processing of magnetic information.