Structural and functional imaging of intact neural systems
- Revolutionary methods developed in the last decade have yielded new insights into many biological systems. Despite these technological advances, many complicated structures such as the brain have continued to defy our understanding. In part, this veil exists because of the necessary trade-offs made by most methods, sacrificing resolution of some dimensions (e.g. functional, temporal) in order to more precisely measure others (e.g. structural, molecular). Recent methods for unbiased, whole-sample analysis with high resolution could eliminate some of these trade-offs and yield a more complete understanding of systems-level interactions in complex structures. In this thesis, I apply whole-system methodologies to characterize a behavioral neural network spanning multiple brain regions and a developmental process in an entire organ, the pancreas. In the first section of this work, I use a model organism, the larval zebrafish, to study the whole-brain response in passive coping. I develop a behavioral challenge protocol that induces passive coping in the larval zebrafish and perform brain-wide calcium imaging of neural activity during the behavioral transition. Recordings of neural activity reveal a slow but striking ramping of activity confined to the lateral habenula, as well as a gradual transition to a reduced level of activity in both the raphe nuclei and the dorsal thalamus. Additionally, I use optogenetic stimulation of the lateral habenula combined with brain-wide imaging to show that activation is sufficient to reduce mobility as well as reduce activity in the raphe. These results provide unbiased evidence of a critical role for the lateral habenula in regulating both immediate and prolonged effects of stress on action selection, whereby either synaptic or membrane properties of lateral habenula neurons encode both prior and on-going experiences. In the second section of this work, I adapt CLARITY, a tissue-clearing technique, to be easily compatible for clearing a variety of heterogeneous and soft tissues and for integration into a standard clinical workflow. After developing a biphasic hydrogel methodology and an automated analysis platform for high-throughput quantitative volumetric analysis of biological features, I validate and apply this approach in the examination of a variety of organs and diseased tissues with a specific focus on the dynamics of pancreatic innervation and islet development in laboratory mouse and human clinical samples. Together, these two sections demonstrate unbiased, whole-sample techniques for: (1) probing the brain-wide neural response in disease-relevant behaviors in a model organism; and (2) characterizing molecular-level phenotypes and development processes in a variety of intact systems.
|Type of resource
|electronic; electronic resource; remote
|1 online resource.
|Burns, Vanessa Marie
|Stanford University, Department of Chemical and Systems Biology.
|Statement of responsibility
|Vanessa Marie Burns.
|Submitted to the Department of Chemical and Systems Biology.
|Thesis (Ph.D.)--Stanford University, 2017.
- © 2017 by Vanessa Marie Burns
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...