We address our research questions by combining behavioral analysis with wireless optogenetics or chemogenetics to manipulate brain activity, fiber photometry to measure neural circuits dynamics, and synaptic physiology and anatomical techniques for mapping brains connections.
How do dopamine neurons transmit information about salient events?
Dopamine neurons make up less than 1 percent of brain’s neurons, but control multiple brain functions, including salience processing in motivated behavior, decision-making and memory. How can a small number of neurons have such a broad impact on brain function? Our lab addresses this question by investigating the different modes the dopamine neurons communicate with other cells in the brain. Dopamine neurons not only release dopamine, but some also co-release glutamate and GABA. We are mapping the distribution of different subtypes of dopamine neurons in the mouse brain using intersectional strategies and focus on understanding how different factors, such as aging or schizophrenia-associated factors, affects this cell diversity and microcircuit function.
What are the brain mechanisms for remembering the seemingly mundane?
Memory systems have evolved to remember events based on their significance so that organisms can anticipate dangerous or pleasant events. The efficiency of this memory system relies heavily on the acquisition and recognition of safe and mundane events, known as the familiarity. Difficulty in recognizing familiar events is a defining feature of cognitive decline in Alzheimer’s disease and thought to produce delusional beliefs in psychosis. Despite its critical roles, the brain mechanisms mediating familiarity remain poorly understood. Our lab is addressing these questions by looking at the connections between the dopamine system and the lateral entorhinal cortex, a region thought to modulate the recognition of familiar events.
What are the neural dynamics that regulate behavioral switching?
The world is extremely complex and the demands of numerous and changing environmental stimuli compete for the organism’s limited cognitive and motor resources. We are interested in understanding the brain circuits that modulate the animal’s choice to respond to relevant (salient) events in the environment. We focus on interactions between memory systems (hippocampal formation) and motivational systems (nucleus accumbens), and how these circuits integrate information about goals and beliefs to control adaptive behavioral switching.