Much of our knowledge of brain function has been gleaned from studies using microelectrodes to characterize the response properties of individual neurons in vivo. However, because it is difficult to accurately determine the location of a microelectrode tip within the brain, it is impossible to systematically map the fine three-dimensional spatial organization of many brain areas, especially in deep structures.
To advance the state-of-the-art in electrode positioning, we’ve developed an array of tools. First, we developed a practical method based on digital stereo microfocal X-ray imaging that makes it possible to estimate the three-dimensional position of each and every microelectrode recording site in “real time” during experimental sessions. Second, we have begun work on a intra-operative structured illumination 3D-imaging technique that allows detailed maps of the skull surface of a rodent to be generated online, allowing precise implant placement and subsequent co-registration with electrodes during experimental session days and weeks later.