An neuronavigation system for structural and functional MRI-guided transcranial magnetic stimulation and neurophysiological recordings in non-human primates

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In this application, funding is requested for a system that can guide the placement of neural recording devices using a procedure known as 'neuro-navigation'. This system makes use of images of the brain obtained using Magnetic Resonance Imaging (MRI) scanners, of the type commonly available in hospitals. MRI images are used that describe both the anatomical structure of the brain (structural MRI), and its activity in response to external sensory stimuli (functional MRI), such as pictures of objects. The neuro-navigation system registers images of the brain using an internal coordinate system, which is specified by a reference device attached to the head during an MRI scan. This reference device is visible in the MRI images. Subsequent to the scan, the system can help guide the insertion of neural probes into specific brain sites, as selected by a researcher from the given MRI images. In order to guide implantation, the system aligns the MRI coordinate system to the physical space of the operating room using infra-red light, which is projected back from the reference device. The device is attached to the head in the same position as it was in the MRI scanner, thus it can be used as the link to align the new physical space to the MRI images. Similar systems are used in neurosurgical suites, for MRI guidance of neurosurgical procedures. The system will allow my laboratory to probe brain activity in our continuing investigation of how the visual brain areas function. It will also allow us to accurately position probes in specific brain sites while studying the mechanisms underlying brain imaging signals, research that has applications in pure science and in diagnostics of neurological diseases. Furthermore, it will allow us to accurately position coils used to stimulate specific brain sites non-invasively with magnetic fields. We use these coils while studying the mechanisms underlying magnetic stimulation of the brain, research that has applications in pure science and in therapy of neurological and psychiatric diseases. Lastly, we intend to improve upon current neuro-navigation techniques, which will be beneficial to researchers who use it in studies of brain and cognition, to clinical neurosurgeons and the Canadian health system as a whole.