Many animals are apparently capable of detecting and orienting to the earth's magnetic field. This is particularly true in environments where visual clues are not reliable, such as underwater, underground, or in the air out of visual contact with land. Despite the widespread existence of an ability to sense the earth's magnetic field in animals we do not yet understand what such a sensor might look like, or how it works. Researchers have found that the seaslug Tritonia detects, and orients to the earth's magnetic field. It's brain is accessible in a living, nearly freely behaving state, and permits monitoring responses to magnetic field changes in single identified brain cells, through electrodes placed inside neurons. This project will attempt to find the magnetic receptors, observe their detailed structure in the transmission electron microscope, and determine how they may work in Tritonia. It is hypothesized that there may be tiny, membrane bound magnetic particles in these cells that are connected to the internal skeleton of the cells. Magnetic fields tugging on the magnet particles may thereby signal the cell membrane, and in this way create an electrical wave that informs the brain. This project will provide new insights into how magnetic fields alter the responses and behavior of any animals having such particles in their cells. It will also provide a training experience for undergraduate students with an interest in research through an apprenticeship training program associated with the project.
