This paper describes improvements and further characterization of a ceramic-based multisite microelectrode for in vivo measurements of L-glutamate. Improvements include increased recording area, insulation deposition using photolithography for more uniform recording sites and forming the microelectrodes using a diamond saw providing smoother microelectrode edges. The new microelectrodes are triangular in shape, 1 cm in length and taper from 1 mm to a 2-5 microm tip. Details on performing in vivo measurements are given, including microelectrode preparation, pitfalls of the recording method and approaches to enhance reproducibility of the technique. The detection limit for L-glutamate was lowered to approximately 0.5 microM and a self-referencing recording technique was utilized to remove interferents as well as decrease noise. Applications of the microelectrodes to study L-glutamate uptake and release in rat prefrontal cortex, cortex, cerebellum and striatum are included.
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http://dx.doi.org/10.1016/s0165-0270(02)00172-3 | DOI Listing |
Anal Chem
February 2017
Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal.
Ceramic-based multisite Pt microelectrode arrays (MEAs) were characterized for their basic electrochemical characteristics and used for in vivo measurements of oxygen with high resolution in the brain extracellular space. The microelectrode array sites showed a very smooth surface mainly composed of thin-film polycrystalline Pt, with some apparent nanoscale roughness that was not translated into an increased electrochemical active surface area. The electrochemical cyclic voltammetric behavior was characteristic of bulk Pt in both acidic and neutral media.
View Article and Find Full Text PDFJ Neurosci Methods
August 2015
Department of Anatomy & Neurobiology, University of Kentucky Chandler Medical Center, Lexington, KY 40536, USA; Department of Pediatrics, University of Kentucky Chandler Medical Center, Lexington, KY 40536, USA; Department of Psychiatry, University of Kentucky Chandler Medical Center, Lexington, KY 40536, USA; Center for Microelectrode Technology, University of Kentucky Chandler Medical Center, Lexington, KY 40536, USA; Parkinson's Disease Translational Research Center of Excellence, University of Kentucky Chandler Medical Center, Lexington, KY 40536, USA. Electronic address:
Background: The aberrant regulation of glutamate has been implicated in numerous psychiatric disorders including drug addiction and attention-deficit/hyperactivity disorder. To understand glutamate signaling and its role in facilitating disease, tools to directly measure glutamate in a complex, neural network are needed.
New Method: The development of a ceramic-based, dual-sided, biomorphic microelectrode array with four recording sites on each side to facilitate a more detailed measurement of glutamate in awake, behaving rodents.
J Neurosci Methods
June 2011
Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536, USA.
Amperometric measurements using microelectrode arrays (MEAs) provide spatially and temporally resolved measures of neuromolecules in the central nervous system of rats, mice and non-human primates. Multi-site MEAs can be mass fabricated on ceramic (Al₂O₃) substrate using photolithographic methods, imparting a high level of precision and reproducibility in a rigid but durable recording device. Although the functional capabilities of MEAs have been previously documented for both anesthetized and freely moving paradigms, the performance enabling intrinsic physical properties of the MEA device have not heretofore been presented.
View Article and Find Full Text PDFBiosens Bioelectron
April 2008
Department of Anatomy & Neurobiology, Center for Microelectrode Technology, University of Kentucky Chandler Medical Center, Lexington, KY 40536-0098, USA.
A ceramic-based microelectrode array (MEA) with enzyme coatings for the accurate measurement of acetylcholine (ACh) in brain tissues is presented. Novel design features allow for self-referencing recordings for improved limits of detection and highly selective measurements of ACh and choline (Ch), simultaneously. Design and fabrication features also result in minimal tissue damage during implantation and improved enzyme coatings due to isolated recording sites.
View Article and Find Full Text PDFConf Proc IEEE Eng Med Biol Soc
April 2008
School of Biomedical Engineering and Health Systems at Drexel University, Philadelphia, PA 19104 USA.
Voltammetry has been used as a method to measure the concentration of monoaminergic neurotransmitters in-vivo. The standard electrode used with voltammetry has been carbon fiber microelectrodes. Despite the advantages of using carbon as a sensing element, carbon fiber microelectrodes have only one site to record the extracellular concentration of neurotransmitters.
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