title: Improved ceramic-based multisite microelectrode for rapid measurements of L-glutamate in the CNS.
abstract: 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.
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000378:metabolism*; D002516:Ceramics / Q000737:chemistry; D018698:Glutamic Acid / Q000032:analysis* / Q000378:metabolism; D008297:Male; D017551:Microdialysis / Q000295:instrumentation* / Q000379:methods; D008839:Microelectrodes / Q000592:standards; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D018698:Glutamic Acid