RII Track-2 FEC: The Creation of Next-Generation Tools for Neuroscience - Noninvasive Radioluminescence Approaches to Optogenetics

Clemson University, Clemson SC

Investigators

Abstract

Non-Technical Description This Research Infrastructure Improvement Track-2 Focused EPSCoR Collaboration (RII Track-2 FEC) proposal is a collaboration between four institutions in South Carolina, Alabama, and New Mexico, namely Clemson University, the University of Alabama Birmingham, the University of New Mexico, and the University of South Carolina. The aim of the project is to extend the uses of the experimental method of optogenetics, which, since its introduction in 2005, has had a transformative impact on neurobiology. This method allows experimenters to activate individual neurons or groups of neurons, with high levels of spatial and temporal control, by flashing light on them. One of the main limitations of standard optogenetics is the inability of visible light to penetrate deep within living tissues. In this project, a system will be developed to allow the use of low-dosage X-rays, rather than visible light, as the activating signal. The project includes multiple opportunities to involve students, especially members of under-represented minority groups. Agreements are in place to host students from Winthrop University and Northern New Mexico College, which serve highly diverse student populations, in existing summer research programs at the research-intensive universities. The project also includes plans for mentoring junior faculty, especially in proposal development. Technical Description This multi-disciplinary project involves step-wise development of novel experimental methods. First, radioluminescent nanoparticles (RLPs) will be produced that emit light when exposed to X-rays. The RLPs will be chemically modified to allow specific covalent attachment to a genetically engineered membrane-bound opsin protein expressed in neurons, ensuring close proximity of the two components for efficient transfer of the light stimulus. The system will be tested (for efficacy and the absence of undesired side effects) in cultured cells, then brain slice preparations, and finally in intact animals (rats and mice). RLPs will be introduced into animals by injection into the cerebrospinal fluid, through which the particles may diffuse into the brain. The effects of X-ray exposure on the behavior of immobilized and freely moving animals will then be tested to verify successful activation of neural cells in the motor and auditory cortexes.