Decades of research in neuroscience, control systems, and robotics have produced elegant theories of how movements can be controlled in both biological and man-made systems. We know a lot less about which motor control principles are used in the mammalian brain, and which specific brain circuits perform the relevant computations. By studying movements performed by mice engaged in well controlled behavior and applying state-of-the-art tools for dissecting neural circuitry, we hope to bridge this gap.
Cortical control of motor primitives
Motor cortex controls flexible parameters of voluntary movements. However, the coordination and timing of different muscle groups is controlled by low-level premotor regions in the brainstem and spinal cord. We’re trying to understand how output signals from motor cortex shape activity in premotor circuits to produce flexible movements.
Architecture of premotor circuits
The motor circuits that control the musculature of the head and neck are contained within the reticular nuclei of the medulla. Little is known about the cell types located in the reticular nuclei, their connectivity, and how they produce coordinated activation of motoneurons. We are unraveling this circuit through a combination of single-cell RNA sequencing (together with the Allen Institute for Brain Science), highly multiplexed in situ hybridization, and viral projection mapping. This effort is vital for understanding how diverse motor systems distributed across the brain are coordinated to produce coherent behavior.
Motor cortex communication pathways
Cortical pyramidal tract neurons form the only direct connections between the motor cortex and motor centers in the midbrain, hindbrain, and spinal cord. Through a combination of transcriptomics, large-scale neuroanatomy, electrophysiology, and behavior, we found that the pyramidal tract is made up of two parallel communication channels each with unique roles in planning and executing flexible movements. Read more about this project in Nature and Scientific American.
Structure of long-range brain circuits
We developed new technology for reconstructing the brain wide projections of single neurons in the mouse brain. This technology forms the core of a large scale project to determine the structure of communication pathways in the mouse brain at an unprecedented level of detail and continues to inform our study of coordination between brain areas.
Transformations in early olfactory circuits
After developing techniques for applying two-photon imaging of ultrasensitive calcium indicators to the olfactory bulb, we revealed new principles for how lateral inhibitory circuits are engaged by sensory stimuli.