Background: Dopamine (DA) is a neurotransmitter involved in movement, reward learning and addiction. Fast-scan cyclic voltammetry (FSCV) has long been an indispensable tool for monitoring real-time DA signaling. Development of polyimide fused silica-encased FSCV microelectrodes have made the technique more suitable for chronic DA monitoring (months) in vivo. Methods: In this study, electrically stimulated DA signals were evoked weekly in an effort to characterize the recovery time and stability of DA signals recorded long-term with silica-encased chronic DA microelectrodes. Additionally, electrical conditioning (etching), previously shown to improve microelectrode sensitivity in vitro, was performed to investigate the long-term impact on DA monitoring in vivo. Changes in sensitivity were assessed by kinetic analysis of recorded DA signals resulting in parameters describing DA release ([DA][subscript p]; the concentration of DA release per stimulus pulse) and uptake (V[subscript max]; maximal rate of DA uptake). Results: Data from this study demonstrate that the peak amplitude of evoked DA signals (DA[subscript max]) significantly decreases after surgery, recovers in about 4.5 weeks, and then stabilizes and remains consistent long-term(> 6 weeks). The same trend holds for kinetic parameters describing DA release and uptake. Additional data also demonstrate that electrical conditioning increases the magnitude and quality of DA signals recorded long- term in vivo. Conclusions: Once recovered, electrically evoked DA signals recorded at the silica- encased chronic DA microelectrode, and resulting kinetic parameters describing DA release and uptake, are stable long-term (months) and can be enhanced with electrical conditioning.
","abstract_html":"<p>Background: Dopamine (DA) is a neurotransmitter involved in movement, reward learning and addiction. Fast-scan cyclic voltammetry (FSCV) has long been an indispensable tool for monitoring real-time DA signaling. Development of polyimide fused silica-encased FSCV microelectrodes have made the technique more suitable for chronic DA monitoring (months) in vivo. Methods: In this study, electrically stimulated DA signals were evoked weekly in an effort to characterize the recovery time and stability of DA signals recorded long-term with silica-encased chronic DA microelectrodes. Additionally, electrical conditioning (etching), previously shown to improve microelectrode sensitivity in vitro, was performed to investigate the long-term impact on DA monitoring in vivo. Changes in sensitivity were assessed by kinetic analysis of recorded DA signals resulting in parameters describing DA release ([DA][subscript p]; the concentration of DA release per stimulus pulse) and uptake (V[subscript max]; maximal rate of DA uptake). Results: Data from this study demonstrate that the peak amplitude of evoked DA signals (DA[subscript max]) significantly decreases after surgery, recovers in about 4.5 weeks, and then stabilizes and remains consistent long-term(> 6 weeks). The same trend holds for kinetic parameters describing DA release and uptake. Additional data also demonstrate that electrical conditioning increases the magnitude and quality of DA signals recorded long- term in vivo. Conclusions: Once recovered, electrically evoked DA signals recorded at the silica- encased chronic DA microelectrode, and resulting kinetic parameters describing DA release and uptake, are stable long-term (months) and can be enhanced with electrical conditioning.</p>","abstract_has_math":false,"creators":["Marr, Eric P."],"institution":null,"degree_name":"Master of Science (MS) in Biology","degree_level":"Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-01-01T08:00:00Z","date_published":"2015-01-01T08:00:00Z","updated_at":"2026-07-24T02:13:16Z","subjects":["Dopamine--Analysis","Neurotransmitters","Microelectrodes","Sprague Dawley rats","Biology"],"languages":[],"rights":["Access is available to all users"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://dc.ewu.edu/theses/299","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Marr, Eric P."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS) in Biology"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Dopamine--Analysis","Neurotransmitters","Microelectrodes","Sprague Dawley rats","Biology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Access is available to all users"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://dc.ewu.edu/theses/299"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Background: Dopamine (DA) is a neurotransmitter involved in movement, reward learning and addiction. Fast-scan cyclic voltammetry (FSCV) has long been an indispensable tool for monitoring real-time DA signaling. Development of polyimide fused silica-encased FSCV microelectrodes have made the technique more suitable for chronic DA monitoring (months) in vivo. Methods: In this study, electrically stimulated DA signals were evoked weekly in an effort to characterize the recovery time and stability of DA signals recorded long-term with silica-encased chronic DA microelectrodes. Additionally, electrical conditioning (etching), previously shown to improve microelectrode sensitivity in vitro, was performed to investigate the long-term impact on DA monitoring in vivo. Changes in sensitivity were assessed by kinetic analysis of recorded DA signals resulting in parameters describing DA release ([DA][subscript p]; the concentration of DA release per stimulus pulse) and uptake (V[subscript max]; maximal rate of DA uptake). Results: Data from this study demonstrate that the peak amplitude of evoked DA signals (DA[subscript max]) significantly decreases after surgery, recovers in about 4.5 weeks, and then stabilizes and remains consistent long-term(> 6 weeks). The same trend holds for kinetic parameters describing DA release and uptake. Additional data also demonstrate that electrical conditioning increases the magnitude and quality of DA signals recorded long- term in vivo. Conclusions: Once recovered, electrically evoked DA signals recorded at the silica- encased chronic DA microelectrode, and resulting kinetic parameters describing DA release and uptake, are stable long-term (months) and can be enhanced with electrical conditioning.
"]},{"key":"dc:title","label":"Title","values":["Long-term characterization of the chronic dopamine microelectrode and effect of electrical conditioning"]}]}],"canonical_facts":{"dc:creator":["Marr, Eric P."],"dc:description.abstract":["Background: Dopamine (DA) is a neurotransmitter involved in movement, reward learning and addiction. Fast-scan cyclic voltammetry (FSCV) has long been an indispensable tool for monitoring real-time DA signaling. Development of polyimide fused silica-encased FSCV microelectrodes have made the technique more suitable for chronic DA monitoring (months) in vivo. Methods: In this study, electrically stimulated DA signals were evoked weekly in an effort to characterize the recovery time and stability of DA signals recorded long-term with silica-encased chronic DA microelectrodes. Additionally, electrical conditioning (etching), previously shown to improve microelectrode sensitivity in vitro, was performed to investigate the long-term impact on DA monitoring in vivo. Changes in sensitivity were assessed by kinetic analysis of recorded DA signals resulting in parameters describing DA release ([DA][subscript p]; the concentration of DA release per stimulus pulse) and uptake (V[subscript max]; maximal rate of DA uptake). Results: Data from this study demonstrate that the peak amplitude of evoked DA signals (DA[subscript max]) significantly decreases after surgery, recovers in about 4.5 weeks, and then stabilizes and remains consistent long-term(> 6 weeks). The same trend holds for kinetic parameters describing DA release and uptake. Additional data also demonstrate that electrical conditioning increases the magnitude and quality of DA signals recorded long- term in vivo. Conclusions: Once recovered, electrically evoked DA signals recorded at the silica- encased chronic DA microelectrode, and resulting kinetic parameters describing DA release and uptake, are stable long-term (months) and can be enhanced with electrical conditioning.
"],"dc:identifier":["https://dc.ewu.edu/theses/299"],"dc:rights":["Access is available to all users"],"dc:subject":["Dopamine--Analysis","Neurotransmitters","Microelectrodes","Sprague Dawley rats","Biology"],"dc:title":["Long-term characterization of the chronic dopamine microelectrode and effect of electrical conditioning"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS) in Biology"]},"updated_at":"2026-07-24T02:13:16Z"}