title: Real-time monitoring of brain tissue oxygen using a miniaturized biotelemetric device implanted in freely moving rats.
abstract: A miniaturized biotelemetric device for the amperometric detection of brain tissue oxygen is presented. The new system, derived from a previous design, has been coupled with a carbon microsensor for the real-time detection of dissolved O(2) in the striatum of freely moving rats. The implantable device consists of a single-supply sensor driver, a current-to-voltage converter, a microcontroller, and a miniaturized data transmitter. The oxygen current is converted to a digital value by means of an analog-to-digital converter integrated in a peripheral interface controller (PIC). The digital data is sent to a personal computer using a six-byte packet protocol by means of a miniaturized 434 MHz amplitude modulation (AM) transmitter. The receiver unit is connected to a personal computer (PC) via a universal serial bus. Custom developed software allows the PC to store and plot received data. The electronics were calibrated and tested in vitro under different experimental conditions and exhibited high stability, low power consumption, and good linear response in the nanoampere current range. The in vivo results confirmed previously published observations on oxygen dynamics in the striatum of freely moving rats. The system serves as a rapid and reliable model for studying the effects of different drugs on brain oxygen and brain blood flow and it is suited to work with direct-reduction sensors or O(2)-consuming biosensors.
authors.affiliation: Department of Neuroscience, Medical School, University of Sassari, Viale S. Pietro 43/b, 07100 Sassari, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Bazzu
authors.forename: Giulia G M
authors.initials: GG
authors.lastname: Puggioni
authors.forename: Sonia
authors.initials: S
authors.lastname: Dedola
authors.forename: Giammario
authors.initials: G
authors.lastname: Calia
authors.forename: Gaia
authors.initials: G
authors.lastname: Rocchitta
authors.forename: Rossana
authors.initials: R
authors.lastname: Migheli
authors.forename: Maria S
authors.initials: MS
authors.lastname: Desole
authors.forename: John P
authors.initials: JP
authors.lastname: Lowry
authors.forename: Robert D
authors.initials: RD
authors.lastname: O'Neill
authors.forename: Pier A
authors.initials: PA
authors.lastname: Serra
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D008297:Male; D008904:Miniaturization; D010100:Oxygen / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013686:Telemetry
chemical_list: D000086:Acetazolamide; D010100:Oxygen