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A Method for Simultaneous Measurements of Bioelectric Activity and Local Tissue PO2 in the CNS

  • A. Lehmenkühler
  • H. Caspers
  • E.-J. Speckmann
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 75)

Abstract

Previous investigations have shown that recordings of tissue PO2 in central nervous structures by means of the Polarographic method may be considerably distorted, if Pt-microelectrodes are used in connection with a remote reference point (4). Such distortions are due to DC potentials generated by neural networks of the CNS in a variety of physiological and pathological conditions (c.f. 2). The bioelectric DC potentials interfere with the polarizing voltage in the Polarographic circuit and can simulate changes in PO2, since a sufficient Polarographie step in the current-voltage curves of Pt-microelectrodes is often missing. To avoid this source of error, a recording device has to be used which allows either to reduce the pick up of DC potentials to a minimum or to compensate for them. These requirements are fulfilled by concentric or double micro-electrodes in which the AgAgCl-reference is coupled to the active Pt-tip at a distance of a few microns (c.f. 4). Meanwhile various technical versions of such electrode arrangements have proved their reliability (s. also 1).

Keywords

Polarize Voltage Bioelectric Activity High Oxygen Pressure Graphic Circuit Polarographic Current 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Literature

  1. 1.
    BAUMGÄRTL, H. and LÜBBERS, D.W. Platinum needle electrode for Polarographic measurement of oxygen and hydrogen. In: M. Kessler et al. (Eds.) Oxygen supply. Theoretical and practical aspects of oxygen supply and microcirculation of tissue. pp. 130–136. Urban und Schwarzenberg, München-Berlin-Wien, 1973Google Scholar
  2. 2.
    CASPERS, H. and SPECKMANN, E.-J. Cortical DC shifts associated with changes of gas tensions in blood and tissue. In: A. Remond (Ed.-in-chief) Handbook of Electroencephalography and Clinical Neurophysiology, Vol. 10 Part A, pp. 41–65. Elsevier, Amsterdam, 1974Google Scholar
  3. 3.
    KUNKE, S., ERDMANN, W., and METZGER, H. A new method for simultaneous PO2 and action potential measurement in microareas of tissue, J.appl.Physiol., 1972, 32: 436–438PubMedGoogle Scholar
  4. 4.
    SPECKMANN, E.-J. und CASPERS, H. Messung des Sauerstoffdrucks mit Platinmikroelektroden im Zentralnervensystem. Pflügers Arch., 1970, 318: 78–81PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1976

Authors and Affiliations

  • A. Lehmenkühler
    • 1
  • H. Caspers
    • 1
  • E.-J. Speckmann
    • 1
  1. 1.Institute of PhysiologyUniv. of Münster44 MünsterFR Germany

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