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You searched for +publisher:"Brown University" +contributor:("Kanold, Patrick"). One record found.

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1. Bellay, Timothy Edward. Ongoing Dynamics of Layer II/III Pyramidal Neurons Organize As Neuronal Avalanches.

Degree: PhD, Neuroscience, 2014, Brown University

The purpose of this thesis was to identify the cellular mechanisms of the ongoing cortical dynamics called “neuronal avalanches” (NA). NA are the hallmark of ongoing activity in the superficial layers of rat, monkey and human cortex found originally in the local field potential (LFP). NA are precisely quantified as cascades of synchrony whose size distribution follow a power law with slope of -3/2. NA signify the balance of propagation under ongoing dynamics where activity neither dies out nor explodes and is quantified by a critical branching parameter of 1. Previous work on NA has centered on ambiguous population measures of synchrony such as the LFP, EEG, fMRI and MEG and thus the cellular basis of NA remains unknown. In this thesis I tested the hypothesis that spiking in local groups of pyramidal neurons (PNs), the major class of cortical excitatory projection neurons, also organizes as NA. If found true, then the precise scaling laws derived for NA at mesoscopic and macroscopic levels of the brain would also apply at the level of the cortical microcircuit. Using two-photon microscopy, I imaged layer II/III PNs expressing genetically encoded calcium indicators (GECI) with single AP sensitivity in awake, head-fixed rats and in spontaneously active cortex cultures. I found that although single PN spiking was highly irregular and random, group firing organized into cascades with the signature of NA. This finding was sensitive to the level of anesthesia in vivo and to the ratio of excitatory to inhibitory balance in vitro, supporting the role of NA in maintaining the healthy, balanced state of ongoing dynamics in the brain. Furthermore in intracellular recordings of PN in acute slices, I found that intracellular membrane potential deflections correlated with specific NA spatial pattern deflections in the LFP. I conclude that NA signify the precise organization of cortical dynamics at rest, from the single cell level in local PN groups to the whole brain. These findings should profoundly inform new theory and experiments on cellular mechanisms of cortex function. Advisors/Committee Members: Plenz, Dietmar (Director), McBain, Chris (Reader), Diamond, Jeffery (Reader), Connors, Barry (Reader), Kanold, Patrick (Reader).

Subjects/Keywords: cortex

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Bellay, T. E. (2014). Ongoing Dynamics of Layer II/III Pyramidal Neurons Organize As Neuronal Avalanches. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:419370/

Chicago Manual of Style (16th Edition):

Bellay, Timothy Edward. “Ongoing Dynamics of Layer II/III Pyramidal Neurons Organize As Neuronal Avalanches.” 2014. Doctoral Dissertation, Brown University. Accessed October 17, 2019. https://repository.library.brown.edu/studio/item/bdr:419370/.

MLA Handbook (7th Edition):

Bellay, Timothy Edward. “Ongoing Dynamics of Layer II/III Pyramidal Neurons Organize As Neuronal Avalanches.” 2014. Web. 17 Oct 2019.

Vancouver:

Bellay TE. Ongoing Dynamics of Layer II/III Pyramidal Neurons Organize As Neuronal Avalanches. [Internet] [Doctoral dissertation]. Brown University; 2014. [cited 2019 Oct 17]. Available from: https://repository.library.brown.edu/studio/item/bdr:419370/.

Council of Science Editors:

Bellay TE. Ongoing Dynamics of Layer II/III Pyramidal Neurons Organize As Neuronal Avalanches. [Doctoral Dissertation]. Brown University; 2014. Available from: https://repository.library.brown.edu/studio/item/bdr:419370/

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