A fundamental mystery of brain science is to understand how networks of neurons assemble during development and function in circuits to enable perception and behavior. Unraveling this mystery requires an understanding of the relationships between the cellular-level properties of circuits – the anatomical “wiring diagram” of connectivity on the one hand, and the functional properties of single neurons and synapses on the other – and the systems-level properties such as sensory responses or motor outputs.

In the Neural Circuits Lab, we are applying a new generation of optical and optogenetic tools to observe both fine-scale circuit features and systems-level responses at the same time, in the living brain. We combine these optical approaches with advanced physiological and anatomical techniques to address previously inaccessible questions about neural circuitry and its development in mammalian visual cortex.

Imaging neural circuit activity in the living brain with 2-photon microscopy
Left: field of cells in mammalian visual cortex labeled with the calcium dye Oregon Green BAPTA-1 AM. Right: Responses of 3 single cells to visual stimuli moving in the indicated directions. The cells exhibit varying degrees of motion selectivity (low to high from left to right). From Li/Van Hooser et al., 2008.