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Chronic monitoring of brain tissue oxygen in freely moving rats from a fully implanted telemetry system
Author(s) -
Russell David Martin,
Garry Emer,
Taberner Andrew,
Budgett David,
Malpas Simon
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1077.6
Subject(s) - telemetry , brain tissue , amperometry , biomedical engineering , potentiostat , chemistry , oxygen , materials science , electrode , medicine , electrochemistry , computer science , telecommunications , organic chemistry
We have developed an implantable telemetry system for the chronic monitoring of in‐vivo brain tissue oxygen. It utilises novel carbon paste electrodes (CPEs, diameter 200μm) for the amperometric detection of physiological concentrations of oxygen in brain ECF. Detection of brain tissue O 2 using CPEs is advantageous over other detection methods as CPEs have been shown to provide long‐term stability. The implanted transmitter (wt 11 gm) has an integrated potentiostat. The voltage is linearly related to the dissolved O 2 concentration. The total RMS noise of the system was 0.23μM and has a bandwidth of 25Hz. We utilised inductive power transfer to enable the telemeter battery to be recharged transcutaneously thus maintaining continuous recording for potentially the lifetime of the animal. The telemeter body was implanted in abdomen of rats and the electrode placed in the striatum with a Stoelting stereotaxic frame. After recovery with the rat in its home cage, the inspired O 2 concentration was varied (10%, 21%, 100%). The observed brain oxygen tension agreed with changes in inspired O 2 concentration. Diamox, a carbonic anhydrase inhibitor also induced changes in striatial O 2 concentrations. The long term stability of the implanted system was shown to be stable for >5 weeks after implantation. This new telemetry system will allow for the measurement of brain tissue oxygen in fully freely‐moving animals.