Circuit Diagrams

ABSTRACT Sleep occupies a third of our lives and sleep-related ailments cost an estimated $100 billion per year, yet the mechanisms governing its regulation remain poorly understood. Despite the substantial progress that has been made in the discovery and understanding of specific sleep-promoting and wake-promoting neuronal and molecular pathways, what is missing is an integrated understanding of how these mechanisms work together in the brain to regulate sleep and wake as whole-brain behavioral states.

Abstract Vision is an active process: we move our head and eyes to explore the sensory world. This is particularly important in situations where a stationary view provides limited information, such as when looking for an object that is occluded or obscured, which is common in complex natural scenes.

Summary Most perceptual, cognitive, and motor functions rely on neuronal activity distributed across multiple networks, often located in different brain areas. In many systems, including the visual system, signaling between areas is bidirectional: lower areas communicate with higher ones via feedforward connections, and higher areas signal to lower areas via feedback. Feedforward pathways are thought to underlie the increasingly sophisticated receptive fields as one ascends the visual hierarchy. The role of feedback signaling in visual processing, in contrast, is poorly understood.

Summary This proposal will investigate the neural dynamics underlying three-dimensional foraging behavior, with three overarching goals. The first is to evaluate the neural computations of foraging in dynamic environments in naturalistic settings. The second is to compare the algorithmic behavioral computations and their neural substrates under naturalistic versus traditional laboratory settings. Most neuroscience studies assume that laboratory behavior has real-world implications, so any differences we observe would have remarkable consequences for the future of neuroscience.

PROJECT SUMMARY In order to forage effectively for food, the brain must integrate innate and learned information about the value of different food odors and use this information to select navigational motor programs. Although a great deal is known about how the brain computes the value of odor stimuli, how it uses this information to guide navigation remains mysterious. Here we propose to investigate the role of a conserved navigation center, the fan-shaped body (FB), in olfactory navigation.

Abstract Our brains have evolved to extract relevant sensory information from rich and complex natural environments in order to drive appropriate behavior. Multiple brain structures can play a role in such processing, and while cortex is often most prominent in mammalian studies, many behaviors can also be mediated by superior colliculus, particular orienting and avoidance responses to salient stimuli.

Motor neurons connect to muscles and comprise the major output of the nervous system. Patterns of neural activity in motor neurons cause temporally precise muscle contractions, producing coordinated and flexible behavior. These patterns are shaped by the connectivity and physiology of premotor circuits in the spinal cord that synapse onto the motor neurons. Premotor circuits combine descending motor commands with sensory feedback signals to drive motor neuron activity.

Project Summary The ability to remember information, whether after short or long delays, is a fundamental human ability. There is enormous research into understanding working memory and long-term memory in isolation, but also a longstanding debate about the interactions between working memory and long-term memory.

Summary Animals actively sample sensory information, which they combine with prior knowledge to make decisions in a sensorimotor feedback loop. Aspects of this complex loop are often studied in isolation, using trial structures and in simplified conditions such as head-restrained animals in virtual reality.

PROJECT SUMMARY How our brain achieves coherent perception by integrating information from parallel sensory pathways distributed across space and time remains a central question in neuroscience. In the auditory system, sound information reaches the cortex via the lemniscal (“primary”) and non-lemniscal (“secondary”) pathways. The non-lemniscal pathways have often been described as slower integrators of multi-sensory information, in contrast to the roles of the lemniscal pathways as fast and reliable relays for sound inputs.