Cortical Representation of Natural Behavior in 3 Dimensions
One of the great questions facing neuroscience is how the brain generates goal-directed motor behavior. More than a century of work has shown that purposeful movements of the body result from neural activity spanning several regions of the brain. In particular, the posterior parietal cortex (PPC) and pre-motor cortex are major components of the cortical motor apparatus, comprising a network through which movements are planned and targeted in space before they are actually made. Historically, these regions have been most studied in monkeys or humans subject performing tasks while physically constrained (monkeys being head-fixed, or humans laying inside a functional scanner). As a result, there is a gap in our understanding of how the PPC-premotor pathway formulates self-paced, natural behaviors in an unrestrained setting. The primary goal of this project is to gain a deeper understanding of the neural coding of self-guided movement in 3D, and to find the neural correlates of behaviors at the timescales at which they naturally occur. To accomplish this we are conducting large-scale population recordings with high-density silicone probes in freely-behaving rats whose movements are tracked with multi-camera 3D tracking systems.
To date, we have found that both PPC and pre-motor cortex exhibit exquisite tuning to 3D postures and movements during different spatial tasks. To better understand the relative contributions of PPC and pre-motor cortex to goal-directed navigational behavior we are using rapid, transient silencing of neural activity via opto- and chemo-genetics. Subsequent experiments in the project will further broaden our understanding of how movement, posture, and planning affect representations in systems upstream and downstream from the PPC-premotor circuit, including prefrontal areas, sensory cortices, retrosplenial cortex or entorhinal cortex.
Through studying how the brains of these animals represent natural patterns of behavior in 3D, we hope to uncover general neural coding principles of goal-directed motor behavior which could be used, for example, to improve the efficiency of brain-controlled prosthetic devices in patients suffering from paralysis. The data obtained from this work could also be applied in the optimization of generative movement algorithms in robotics-- a field which is intent on producing machines to assist humans in hazardous environments and rescue situations.
This project is an extension of work performed by our group during the past few years (FOTS application 5668, approved 2013), and thanks to advances in the design of neurophysiological recording probes, we estimate that we can achieve the goals of the work with approximately half the number of animals proposed in our previous work (upper limit of 115 rats, though it is likely fewer will be used). Any distress to the animals would be in the post-surgical recovery period, during which animal health and welfare are monitored very closely. We wish to emphasize that our scientific success requires that the animals are healthy, well-nourished and behaving vigorously.
Funding for the work is provided by the Norwegian Research Council (Centre of Excellence scheme), the Kavli Foundation, and the European Research Council.
To date, we have found that both PPC and pre-motor cortex exhibit exquisite tuning to 3D postures and movements during different spatial tasks. To better understand the relative contributions of PPC and pre-motor cortex to goal-directed navigational behavior we are using rapid, transient silencing of neural activity via opto- and chemo-genetics. Subsequent experiments in the project will further broaden our understanding of how movement, posture, and planning affect representations in systems upstream and downstream from the PPC-premotor circuit, including prefrontal areas, sensory cortices, retrosplenial cortex or entorhinal cortex.
Through studying how the brains of these animals represent natural patterns of behavior in 3D, we hope to uncover general neural coding principles of goal-directed motor behavior which could be used, for example, to improve the efficiency of brain-controlled prosthetic devices in patients suffering from paralysis. The data obtained from this work could also be applied in the optimization of generative movement algorithms in robotics-- a field which is intent on producing machines to assist humans in hazardous environments and rescue situations.
This project is an extension of work performed by our group during the past few years (FOTS application 5668, approved 2013), and thanks to advances in the design of neurophysiological recording probes, we estimate that we can achieve the goals of the work with approximately half the number of animals proposed in our previous work (upper limit of 115 rats, though it is likely fewer will be used). Any distress to the animals would be in the post-surgical recovery period, during which animal health and welfare are monitored very closely. We wish to emphasize that our scientific success requires that the animals are healthy, well-nourished and behaving vigorously.
Funding for the work is provided by the Norwegian Research Council (Centre of Excellence scheme), the Kavli Foundation, and the European Research Council.