Long-term characterization of the chronic dopamine microelectrode and effect of electrical conditioning

<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>

Name thesis:degree_name

Master of Science (MS) in Biology

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year

2015

Author dc:creator

• Marr, Eric P.

• Dopamine--Analysis
• Neurotransmitters
• Microelectrodes
• Sprague Dawley rats
• Biology

Statement dc:rights

• Access is available to all users

Repository record dc:identifier

https://dc.ewu.edu/theses/299

OAI identifier oai:identifier

oai:dc.ewu.edu:theses-1298