Research Projects

Project Summary/Abstract This project aims to investigate the circuit mechanisms enabling an ethologically relevant sensorimotor transformation. Specifically, we characterize the neural basis for rapid vocal exchanges in the singing mouse (Scotinomys teguina), a highly vocal neotropical rodent species capable of producing an audible, stereotyped song. Pairs of S. teguina often precisely coordinate the timing of their vocalizations in a process known as countersinging.

Working memory maintenance is fundamental for the orderly pursuit of goals in the face of irrelevant, distracting stimuli. Both prefrontal and visual areas are thought to contribute to the maintenance of items in working memory, but the exact nature of the interaction between these areas has yet to be causally examined. This proposal combines neurophysiological recordings of single unit activity and local field potentials with pharmacological manipulations of the prefrontal cortex, to determine its contribution to memory-driven changes in neural activity and synchrony within visual areas.

ABSTRACT Visual learning is critical to the lives of human and non-human primates. Visuomotor association, the assignment of an arbitrary symbol to a particular movement (like a red light to a braking movement), is a well- studied form of visual learning. This proposal tests the hypothesis that the brain accomplishes visuomotor associative learning using an anatomically defined closed-loop network, including the prefrontal cortex, the basal ganglia, and the cerebellum.

The mammalian cortex plays a critical role in integrating multiple streams of information to guide adaptive behavior. For example, head direction (HD) information is combined with visual and spatial input in the mouse retrosplenial cortex (RSC). Accurate integration of these signals is a necessary component of navigation: recognizing a distant landmark while facing north vs. facing south has very different interpretations for one's position and future actions.

Project Summary Dopamine plays a central role in motivation and reinforcement learning, allowing animals to take advantage of their current circumstances to optimize both present and future behavior. Yet reconciling the diverse roles of dopamine has remained a challenge, in part due to the difficulty of understanding how a single neuromodulator can convey different signals to its cellular targets in distinct behavioral contexts.

PROJECT SUMMARY/ABSTRACT Humans and numerous other species live in complex social environments, requiring many of our most important decisions to be made in the context of social interactions. All of our social relationships rely on our ability to make context-appropriate decisions, including significant ties with committed partners, family, and friends. The social decision-making (SDM) network hypothesis suggests that the expression of a given social behavior is reflected by the overall activity of a network of structures rather than activity of any single structure.

Abstract The focus of this BRAIN Initiative funding opportunity is to use “innovative approaches to understand how circuit activity gives rise to a specific behavior”. Cognitive behaviors arise from collective interactions of multiple brain systems.

Abstract The neurobiology of perceptual decision-making elucidates fundamental neural mechanisms of higher cognitive function, the understanding of which will inspire new strategies to treat neurological and psychiatric diseases affecting thought, perception and awareness. The inquiry focuses on processes that intervene between the acquisition of sensory evidence and commitment to a proposition, behavioral choice, or plan.

Project Summary Understanding how neural circuits create animal behavior requires knowing the system-wide activity patterns that connect sensory experience to motor activities, all within the full set of feedback loops by which actuated motor decisions modulate the animal's perceptions of itself and the outside world during naturally executed and unrestrained behaviors. Mechanistic understanding further requires interpretation of system-wide activity patterns in terms of the connectivity, synaptic, and cellular properties of all relevant neurons.

Project Summary/Abstract Impairments in social functioning is a prominent, debilitating symptom in many neuropsychiatric disorders, such as autism spectrum disorders, schizophrenia, and major depressive disorder. Currently the neural underpinnings of these social deficits are poorly understood, and effective therapeutic approaches are still lacking. Elucidation of the neural circuit mechanisms for social behaviors will improve our understanding of the disease mechanisms of neuropsychiatric disorders, facilitating the development of potent treatments.