During goal-directed behavior, animals integrate information of sensory cues, internal representation of goals and trial history of choice-outcome to generate specific motor action. This process also involves experience-dependent modifications in sensory representation and behavioral strategy, which allows the animal to adapt to changes in the relations between stimulus, response and outcomes. We are interested in understanding the neural and circuit basis of visually guided behavior, decision-making, associative learning and behavioral flexibility. Using the mouse model, we address these issues by studying several brain regions important for perceptual decision making and goal-directed behavior: visual cortex, orbitofrontal cortex, anterior cingulate cortex, secondary motor cortex, higher-order thalamus, and basal ganglia. Our techniques include multi-electrode recordings, fiber photometry, calcium imaging, optogenetic/pharmacogenetic manipulation, immunohistochemistry, and mouse behavior.

Neural mechanism underlying associative learning and reward-related behavior

The orbitofrontal cortex (OFC) plays an important role in decision making, learning and outcome-guided behavior. Our recent study revealed that OFC projection to V1 contributes to visual associative learning by modulating V1 responses to reward-irrelevant stimulus. We recently mapped the whole-brain inputs of projection specific OFC neurons, and found that different projection-defined OFC neurons received inputs from similar cortical and thalamic regions, particularly in somatomotor areas, anterior cingulate cortex (ACC), and mediodorsal nucleus of thalamus (MD). We also mapped the distribution of parvalbumin (PV) or somatostatin (SST) neurons innervated by neurons in specific OFC subregion, and found that OFC neurons targeted PV and SST neurons in a diverse range of regions, including cortex, striatum, pallidum, and thalamus. We are currently studying the role of ACC-to-OFC and MD-to-OFC projections in associative learning, and the role of projection from OFC to the reticular nucleus of the thalamus in reversal learning.

Neural circuit mechanism underlying goal-directed visuomotor behavior

The secondary motor cortex (M2 or MOs) plays an important role in cue-guided actions and memory-guided behaviors. Our previous study showed that M2 contributes to flexible action selection during visual categorization, and the projection from M2 to dorsal striatum is essential for withholding response to reward-irrelevant sensory stimulus. We are currently studying the role of thalamic or cortical input to M2 in visual perceptual decision-making behavior.