Title Information
Title
Models of Neurovascular Coupling in the Brain
Name: Personal
Name Part
Witthoft, Alexandra Elisabeth
Role
Role Term: Text
creator
Origin Information
Copyright Date
2015
Physical Description
Extent
xiv, 163 p.
digitalOrigin
born digital
Note
Thesis (Ph.D. -- Brown University (2015)
Name: Personal
Name Part
Karniadakis, George
Role
Role Term: Text
Director
Name: Personal
Name Part
Vlahovska, Petia
Role
Role Term: Text
Reader
Name: Personal
Name Part
Moore, Christopher
Role
Role Term: Text
Reader
Name: Personal
Name Part
Jones, Stephanie
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Biomedical Engineering
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
We develop three new models of neurovascular coupling at each interface of the neurovascular unit. The neurovascular unit comprises neurons, microvessels, and astrocytes, a type of glial cell that mediates neurovascular communication. We first develop a bidirectional dynamical model of an astrocyte that both controls and responds to dilations of an arteriole. The astrocyte induces dilation by releasing potassium near the vessel in response to increased neural activity, a phenomenon known as functional hyperemia. In the reverse direction, the astrocyte responds to the arteriole movement via mechanosensitive ion channels on its membrane which contacts the arteriole wall. We perform several sensitivity studies of the model, employing both global parameter sensitivity analysis using stochastic collocation, and various model sensitivity studies. In the second model, we consider the neuron-vessel interface, where we simulate a small network of cortical interneurons in contact with a dilating vessel. These perivascular interneurons express mechanosensitive pannexin channels that respond to vessel dilations and constrictions. We use our model to explore how changes in the neural network structure affect the function of the neurovascular connectivity. Our third model is a discrete particle model of a multi-layer fiber-reinforced anisotropic arterial wall, which we develop using the Dissipative Particle Dynamics (DPD) method. The model is constructed based on the true microstructure of the wall and provides an accurate description of the biaxial mechanical behavior of arteries, which we validate with experimental results provided by collaborators. In addition, we add an active mechanism to the discrete particle wall in order to model the arteriolar smooth muscle cell contraction in response to changes in internal pressure (causing the arteriole to constrict with rising pressure) as well as extracellular potassium. We combine the DPD model with the dynamical astrocyte model as a bidirectional system: the vessel dilates with astrocytic potassium release, and the adjacent astrocyte reacts to changes in vessel dilation. The DPD arteriole model provides a bridge between neurovascular model and complex blood flow simulations in DPD, in which existing DPD red blood cell models can be leveraged.
Subject
Topic
neurovascular coupling
Subject
Topic
DPD
Subject
Topic
arteriole
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/819380")
Topic
Astrocytes
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20150601
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z00Z71N9
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations