Communication between Networks: Context, Inhibition, and Neuromodulation
In real world situations, rapidly changing contexts can shift the meaning of a sensory stimulus, requiring an animal to change its response on the fly. This ability to flexibly and appropriately adjust behavioral responses in changing contexts is critical not only for survival, but also to thrive in society. Indeed, disruptions in this flexibility characterize many brain disorders. Underlying behavioral flexibility is the modulation of information processing in the brain, and the goal of my lab’s research is to understand the circuit mechanisms that underlie the contextual modulation of information processing across the cerebral cortex.
Optical tools for monitoring and manipulating specific populations of neurons in vivo allow us to dissect the circuit mechanisms that implement contextual changes in the brain’s responses to sensory stimuli. We use two-photon imaging of calcium responses in neural populations, and genetic labeling of specific neuronal cell classes to measure spike-related activity in large numbers of neurons simultaneously. Optogenetics are used to manipulate the activity of specific cell populations, defined either by cell type or by projection target. We bring these optical circuit dissection tools together in mice performing perceptual tasks in virtual reality, for tight experimental control of the behavioral relevance of sensory stimuli.
The major research focus currently under way in my lab is to determine how excitatory and inhibitory neurons interact to gate the flow of information between brain regions in changing behavioral contexts. These experiments will lead to the development of testable models of the mechanisms underlying communication between cortical networks, with relevance for brain disorders with altered network communication, such as autism and schizophrenia.