The ability to temporally and spatially activate defined sets of neurons using optogenetics has revolutionized neuroscience. While powerful, this technology requires the delivery of light, which is often problematic in vertebrate systems. To overcome this limitation the Keays lab is developing novel magnetogenetic tools to enable remote activation of specific neurons in response to a magnetic stimulus. In designing and building an artificial magnetoreceptor we are drawing on the substrates and principles, that nature employs for the same task.
We are taking two different approaches. In the first instance we are developing a system to generate biogenic magnetite that is coupled to a mechanosensitive channel. In addition to magnetotactic bacteria it is known that chitons, bees, and vertebrates have the capacity to produce intracellular magnetite. The second approach we are developing relies on biogenic iron-oxide crystals that are coupled to thermosensitive calcium channels. The temperature of these crystals can be increased by application of an oscillating magnetic field, thereby activating the channel.