Probing the motor cortical dynamics of flexible feedback control

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Abstract/Contents

Abstract
Despite the apparent effortlessness with which we control our limbs, the physics of the skeletal muscle system that allows you to move and interact with the world are complex. Consequently, executing crisp and precise movements presents a complex control problem to the nervous system. In this thesis, we probe the neural computations in primary motor cortex (M1) and dorsal premotor cortex (PMd) that subserve reaching movements. We record neural activity using electrodes during highly controlled reaching movements performed by rhesus macaques. These neuronal population data were analyzed and modeled using techniques borrowed from the theories of dynamical systems and of dimensionality reduction. We employ both direct neuronal perturbations delivered via optogenetic activation or electrical microstimulation and mechanical perturbations of the arm facilitated by a novel, haptic reaching paradigm. We used engineered tools for observing and perturbing the neural circuits of the primate motor system, enabling dynamical models of neuronal computation to be formulated, validated, and refined. We present three major scientific results, enabled by several technical advances. First, we develop an extended array of optogenetic tools in squirrel monkeys for optical activation and inhibition of genetically and anatomically-targeted neuronal populations. Second, we utilize optogenetic activation in motor cortex of reaching macaques and analyze the robust, local neuronal dynamics which facilitate rapid recovery from this perturbation. Third, we develop an artifact rejection method which we use to directly observe the cortical response to electrical microstimulation, which we then contrast with optogenetic perturbation. Fourth, we apply ideas from optimal feedback control theory to demonstrate that the selection of task-appropriate control policies during reaching is strongly reflected in motor cortical preparatory activity. Lastly, we discuss the need for two-photon calcium imaging in awake, behaving non-human primates and report significant progress towards translating these tools from rodent models.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2016
Issuance monographic
Language English

Creators/Contributors

Associated with O'Shea, Daniel J
Associated with Stanford University, Department of Neurosciences
Primary advisor Shenoy, Krishna V. (Krishna Vaughn)
Thesis advisor Shenoy, Krishna V. (Krishna Vaughn)
Thesis advisor Deisseroth, Karl
Thesis advisor Newsome, William T
Thesis advisor Raymond, Jennifer L
Advisor Deisseroth, Karl
Advisor Newsome, William T
Advisor Raymond, Jennifer L

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Daniel J. O'Shea.
Note Submitted to the Department of Neurosciences.
Thesis Thesis (Ph.D.)--Stanford University, 2016.
Location https://purl.stanford.edu/sm819jv1898
Location https://doi.org/10.25740/sm819jv1898

Access conditions

Copyright
© 2016 by Daniel Joseph O'Shea

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