Brain and Cognitive Sciences

Our laboratory studies how the biophysical features of individual neurons endow neural circuits with powerful processing capabilities, ultimately facilitating the complex computations required to drive adaptive behavior.  A principal focus of our work is the role of dendrites, the elaborate tree-like structures where neurons receive the vast majority of afferent input.  The spatial arrangement of synaptic contacts on dendrites and the interaction of various biophysical mechanisms enable complex integration of synaptic inputs – our hypothesis is that circuit-level computations are built out of these fundamental operations.

BIOPHYSICS & SINGLE-CELL COMPUTATION

The morphological features and local ion channel mechanisms in specific dendritic compartments strongly influence how neurons integrate their inputs.  We combine brain slice electrophysiology, two-photon imaging, and biophysical modeling to investigate the rules and mechanisms supporting different forms of input-output processing across mammalian species.  

NEURONAL COMPUTATION IN THE BEHAVING ANIMAL

How do biophysical mechanisms influence circuit-level computation during behavior?  To address this question, we combine 2-photon imaging and multi-unit electrophysiological recording techniques with novel rodent behavioral paradigms to measure the activity of neuronal populations including subcellular compartments.  This allows us to evaluate the engagement of dendritic mechanisms as a function of circuit dynamics during complex behaviors.  These experiments are complemented by detailed anatomical and single-cell physiological investigations in brain slices.

HEAD-DIRECTION COMPUTATIONS

Head direction is critical for efficient navigation and provides an experimentally tractable system with which to study multimodal integration in neural circuits.  We use state-of-the-art chronic tetrode implants to record HD activity while mice perform goal-directed navigation in darkness and reorient to visual landmarks.  These experiments are combined with anatomical, physiological, and optogenetic techniques, as well as novel behavioral and computational methods, to dissect the cellular and circuit architecture of head direction representations.