FACULTY

Sensation as an active process: What are the mechanics that allow us to physically interact with the world around us? Touching, grasping, and location all rely on an intimate understanding of where our body is relative to the world around us. Yet the neural substrate for this coordinate transformation, which combines reference signals of body position with exafferent signals of direct sensory stimulation, remains largely an enigma. The Kleinfeld laboratory makes use of the vibrissa scanning sensorimotor system to delineate the neuronal basis for this sensorimotor percept. The vibrissae are the focal point of nested feedback loops that close at the level of brainstem up through the neocortex. Their research addresses dynamics in the low-level brainstem loop and selected high-order cortical loops, with emphasis on the interaction of these two pathways. Of note, recent and ongoing work delineates how the high-order loop mediates the transformation from motor-centric coordinates to real-space coordinates in the planning and execution of movement.

Cortical blood flow dynamics: Neuronal activity has a high metabolic load that naturally leads to a tight coupling between electrical signaling in the brain and blood flow and oxygenation. The Kleinfeld laboratory studies cortical blood flow and neurovascular coupling at its most fundamental level, that of single capillaries and single neurons, as a means to study the relation of flow to vascular topology and neuronal activity. Results from this effort have connected aspects of resilient versus fragile blood flow to the topology of the underlying vasculature. Ongoing work involves completion of an “angiotome”, the complete vectorized map of the vasculature of the brain, and, second, unraveling the logic of molecular signaling that relates the activity of different neuronal subtypes to changes in local blood flow.