PROJECT SUMMARY/ABSTRACT Higher brain functions include the ability to learn expectations about the world, update those expectations appropriately when given new sensory information, and use those continually updating expectations to guide behavior. How neural circuits implement these flexible information-processing dynamics is not known.
Optical voltage imaging analysis of the cellular and network mechanisms of deep brain stimulation Deep brain stimulation (DBS) directly stimulates brain tissue via implanted electrodes. DBS has emerged as a well-established therapy, FDA approved for several neurological and psychiatric disorders, and is increasingly explored for a variety of brain diseases. However, the neurophysiological mechanisms of DBS remain largely unknown. DBS therapeutic outcomes and time courses are diverse and depend on the specific disease conditions targeted.
The underlying mechanisms of brain stimulation in humans are poorly understood, especially at the level of gene expression. To address this gap in knowledge, we propose a series of three experiments that take advantage of the opportunity to obtain high-quality human neural tissue from neurosurgical patients in order to measure the impact of brain stimulation on gene expression. Our experiments will generate data to explicate changes at the level of gene expression that underlie brain circuit changes elicited by stimulation.
Project Summary: The decision to commence a new behavior often requires termination of the ongoing behavior. This implies that the many drive states produced by an animal impact not only the neural circuits underlying their directly associated behaviors, but also those of many other behaviors. My lab has shown that the mating behaviors of male Drosophila are under motivational control and may be abandoned in the presence of stimuli evoking competing drives—depending on the relative intensities of the contending drives.
Project Summary/Abstract The overall goal of this project is to determine how output from the basal ganglia influences cerebral cortical activity in the processes of decision making, motor planning, and movement execution. The studies will employ mice as the best suited species in order to bring modern optogenetic and genetically encoded sensor technologies to bear on this critical gap in our understanding of brain function. In aim 1 we address the impact of basal ganglia output on network activity in cortex across sensory and motor areas.
Neural computation for innate behaviors in the superior colliculus The long-term goal of the proposed research is to understand how the brain makes sense of the onslaught of sensory data to extract just the few bits of relevant knowledge needed to make a decision. Specifically we will focus on innate behaviors of the laboratory mouse, such as the escape from a threat, the pursuit of small prey, and visual navigation.
Project Summary Behavior is movement, and the effective and efficient execution of movement has served as a fundamental evolutionary force shaping the form and function of the nervous system. Control of the forelimbs to interact with the world is one of the most essential achievements of the mammalian motor system, yet unfortunately these behaviors are particularly vulnerable to disease and injury. The execution of skilled limb movements requires the continuous refinement of motor output across dozens of muscles, suggesting the existence of feedback pathways that enable rapid adjustments.
SUMMARY To date, fundamental understanding of which features of odorants are decoded by the brain, and how information about these features is channeled through the olfactory system is still lacking. Odorants are sensed by the olfactory sensory neurons (OSNs) in the olfactory epithelium expressing specialized odorant receptors (ORs).
Abstract The cerebellum is critical for learning and executing coordinated, well-timed movements. The cerebellar cortex seems to have a particular role in learning to time movements. Since the 1960's and 70's, we have known the architecture of the cerebellar microcircuit, but most analyses of cerebellar function during behavior have focused on Purkinje cells.
Abstract To survive, living organisms must collect information about their environment and use it to select appropriate behaviors. However, information from the environment is often noisy, incomplete and ambiguous. Currently, no theory or model comprehensively explains how nervous systems solve the problem of navigation based on noisy information.
