Grant: Research Tools and Instruments - Category 1 (<$150,000)

One of the fundamental goals of neuroscience is to understand how different types of neurons, across different brain regions, interact to guide behaviour. This goal has been tremendously challenging due to the many types of cells in the brain and their vast interconnectedness. Even when specific types of cells can be altered, results are often inconclusive since manipulations are typically slow and irreversible, allowing the brain to mask any changes by compensation. Also, few techniques have been able to alter neurons at the high speeds of information processing used by the brain, leaving many brain-behaviour relationships untestable. Optogenetic methods, however, have revolutionized neuroscience research by overcoming many of these barriers. This technology is based on the discovery that light-sensitive proteins, found naturally in algae and bacteria, can be artificially introduced into specific types of neurons and in specific brain regions. These proteins therefore confer light-sensitivity to those neurons, but not neighboring neurons, enabling them to be rapidly turned on and off when the brain is illuminated with light. Dr. Snyder will use this optogenetic equipment to determine the behavioural function of new neurons that are born in the adult brain versus those that are born during early development. Dr. Floresco will use this equipment to identify how a diverse network of brain regions interacts to regulate behavioural flexibility and decision-making. Both of these lines of research are highly-dependent on techniques that can manipulate subpopulations of neurons that are embedded in larger, complex networks as animals learn, recall and make decisions. The state of the art optogenetics equipment described in this proposal will therefore lead to major advances in our understanding of how neural circuits in the brain govern behaviour.