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Manipulating and Understanding the Cultured Neuronal Network through Conducting Polymers

Stauffer, William Richard (2011) Manipulating and Understanding the Cultured Neuronal Network through Conducting Polymers. Doctoral Dissertation, University of Pittsburgh.

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    Abstract

    Conducting polymers are class of polymer that can be synthesized directly on conductive substrates and incorporate various functional molecules into it. Its conductivity and customizability make it an ideal interface material for neuronal network research. In the first phase of this thesis, the incorporation of laminin fragments into conducting polymer films is investigated. The laminin fragments are shown to produce low impedance surfaces for neuronal recording. Furthermore, it is shown that the incorporated laminin fragments promote the adhesion of neurons to the surface. These results could provide a means for promoting a stable interface for chronic recording devices.In the second phase of this thesis, In vitro multielectrode arrays provide a framework for studying polypyrrole-mediated controlled release of neurochemicals from microelectrodes, and neuronal network dynamics in a controlled setting. We have developed a technique to achieve transient and local inhibition of synaptic transmission in cultured networks. Conducting polymer films containing the glutamate receptor antagonist CNQX are synthesized directly on the microelectrodes in the recording array. Release of CNQX is achieved through a brief electrical pulse. Through single cell patch-clamp recording, the effectiveness of CNQX release on inhibiting excitatory post-synaptic currents (EPSC) is characterized as a function of distance and time from the releasing electrode, and evidence is shown supporting a diffusion-mediated process following release. At the network level, simultaneous patch-clamp and extracellular recordings are used to characterize stimulus-evoked responses from the network. Cross correlation and a model-based variable clustering technique identify functional connectivity in a neuronal network response to electrical stimuli. Use of the controlled release of CNQX in conjunction with these techniques will allow us to examine the functional clustering of neurons in response to a given stimulation, and how a functional cluster is affected by transient, local inhibition in the network.


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    Item Type: University of Pittsburgh ETD
    ETD Committee:
    ETD Committee TypeCommittee MemberEmailORCID
    Committee ChairCui, X Tracyxic11@pitt.edu
    Committee MemberSchwartz, Andrewabs21@pitt.edu
    Committee MemberTyler-Kabara, Elizabethelizabeth.tyler-kabara@chp.edu
    Committee MemberBi, Guoqiangguoqiang.bi@gmail.com
    Committee MemberKass, Robertkass@stat.cmu.edu
    Title: Manipulating and Understanding the Cultured Neuronal Network through Conducting Polymers
    Status: Unpublished
    Abstract: Conducting polymers are class of polymer that can be synthesized directly on conductive substrates and incorporate various functional molecules into it. Its conductivity and customizability make it an ideal interface material for neuronal network research. In the first phase of this thesis, the incorporation of laminin fragments into conducting polymer films is investigated. The laminin fragments are shown to produce low impedance surfaces for neuronal recording. Furthermore, it is shown that the incorporated laminin fragments promote the adhesion of neurons to the surface. These results could provide a means for promoting a stable interface for chronic recording devices.In the second phase of this thesis, In vitro multielectrode arrays provide a framework for studying polypyrrole-mediated controlled release of neurochemicals from microelectrodes, and neuronal network dynamics in a controlled setting. We have developed a technique to achieve transient and local inhibition of synaptic transmission in cultured networks. Conducting polymer films containing the glutamate receptor antagonist CNQX are synthesized directly on the microelectrodes in the recording array. Release of CNQX is achieved through a brief electrical pulse. Through single cell patch-clamp recording, the effectiveness of CNQX release on inhibiting excitatory post-synaptic currents (EPSC) is characterized as a function of distance and time from the releasing electrode, and evidence is shown supporting a diffusion-mediated process following release. At the network level, simultaneous patch-clamp and extracellular recordings are used to characterize stimulus-evoked responses from the network. Cross correlation and a model-based variable clustering technique identify functional connectivity in a neuronal network response to electrical stimuli. Use of the controlled release of CNQX in conjunction with these techniques will allow us to examine the functional clustering of neurons in response to a given stimulation, and how a functional cluster is affected by transient, local inhibition in the network.
    Date: 30 June 2011
    Date Type: Completion
    Defense Date: 19 November 2008
    Approval Date: 30 June 2011
    Submission Date: 06 April 2009
    Access Restriction: 5 year -- Restrict access to University of Pittsburgh for a period of 5 years.
    Patent pending: No
    Institution: University of Pittsburgh
    Thesis Type: Doctoral Dissertation
    Refereed: Yes
    Degree: PhD - Doctor of Philosophy
    URN: etd-04062009-012839
    Uncontrolled Keywords: AMPA; AP5; clustering; CNQX; conducting polymer; correlation; cross-correlation; cultured neuronal network; cultured neurons; electrochemical release; glutamate; local release; network statistics; neuronal network; polypyrrole
    Schools and Programs: Swanson School of Engineering > Bioengineering
    Date Deposited: 10 Nov 2011 14:34
    Last Modified: 20 Apr 2012 11:38
    Other ID: http://etd.library.pitt.edu/ETD/available/etd-04062009-012839/, etd-04062009-012839

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