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Functional, Clustered, Feedforward, and Mesoscale Brain Networks


Billeh, Yazan Nicola (2016) Functional, Clustered, Feedforward, and Mesoscale Brain Networks. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z9DB7ZSX.


The brain is a network spanning multiple scales from subcellular to macroscopic. In this thesis I present four projects studying brain networks at different levels of abstraction. The first involves determining a functional connectivity network based on neural spike trains and using a graph theoretical method to cluster groups of neurons into putative cell assemblies. In the second project I model neural networks at a microscopic level. Using diferent clustered wiring schemes, I show that almost identical spatiotemporal activity patterns can be observed, demonstrating that there is a broad neuro-architectural basis to attain structured spatiotemporal dynamics. Remarkably, irrespective of the precise topological mechanism, this behavior can be predicted by examining the spectral properties of the synaptic weight matrix. The third project introduces, via two circuit architectures, a new paradigm for feedforward processing in which inhibitory neurons have the complex and pivotal role in governing information flow in cortical network models. Finally, I analyze axonal projections in sleep deprived mice using data collected as part of the Allen Institute's Mesoscopic Connectivity Atlas. After normalizing for experimental variability, the results indicate there is no single explanatory difference in the mesoscale network between control and sleep deprived mice. Using machine learning techniques, however, animal classification could be done at levels significantly above chance. This reveals that intricate changes in connectivity do occur due to chronic sleep deprivation.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Neural Networks, Mesoscale Brain Networks, Functional Connectivity, Cell Assemblies, Feedforward Networks
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Computation and Neural Systems
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Koch, Christof
Thesis Committee:
  • Siapas, Athanassios G. (chair)
  • Murray, Richard M.
  • Koch, Christof
  • Meister, Markus
Defense Date:18 March 2016
Non-Caltech Author Email:ynb06.imperial (AT)
Record Number:CaltechTHESIS:05162016-100757711
Persistent URL:
Related URLs:
URLURL TypeDescription adapted for ch. 2 adapted for ch. 3 adapted for ch. 5
Billeh, Yazan Nicola0000-0001-5200-4992
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9721
Deposited By: Yazan Billeh
Deposited On:23 May 2016 23:04
Last Modified:30 Aug 2022 22:38

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