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Spontaneous Fluctuations of PO2 in the Rabbit Somatosensory Cortex

  • Robert A. LinsenmeierEmail author
  • Daniil P. Aksenov
  • Holden M. Faber
  • Peter Makar
  • Alice M. Wyrwicz
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 876)

Abstract

In many tissues, PO2 fluctuates spontaneously with amplitudes of a few mmHg. Here we further characterized these oscillations. PO2 recordings were made from the whisker barrel cortex of six rabbits with acutely or chronically placed polarographic electrodes. Measurements were made while rabbits were awake and while anesthetized with isoflurane, during air breathing, and during 100 % oxygen inspiration. In awake rabbits, 90 % of the power was between 0 and 20 cycles per minute (cpm), not uniformly distributed over this range, but with a peak frequently near 10 cpm. This was much slower than heart or respiratory rhythms and is similar to the frequency content observed in other tissues. During hyperoxia, total power was higher than during air-breathing, and the dominant frequencies tended to shift toward lower values (0–10 cpm). These observations suggest that at least the lower frequency fluctuations represent efforts by the circulation to regulate local PO2. There were no consistent changes in total power during 0.5 or 1.5 % isoflurane anesthesia, but the power shifted to lower frequencies. Thus, both hyperoxia and anesthesia cause characteristic, but distinct, changes in spontaneous fluctuations. These PO2 fluctuations may be caused by vasomotion, but other factors cannot be ruled out.

Keywords

Oxygen Cerebral cortex Vasomotion Rabbit Anesthesia 

References

  1. 1.
    Manil J et al (1984) Properties of the spontaneous fluctuations in cortical oxygen pressure. Adv Exp Med Biol 169:231–239CrossRefPubMedGoogle Scholar
  2. 2.
    Hudetz AG et al (1998) Spontaneous fluctuations in cerebral oxygen supply. An introduction. Adv Exp Med Biol 454:551–559CrossRefPubMedGoogle Scholar
  3. 3.
    Braun RD, Linsenmeier RA, Yancey CM (1992) Spontaneous fluctuations in oxygen tension in the cat retina. Microvasc Res 44:73–84CrossRefPubMedGoogle Scholar
  4. 4.
    Lysiak JJ, Nguyen QAT, Turner TT (2000) Fluctuations in rat testicular interstitial oxygen tensions are linked to testicular vasomotion: persistence after repair of torsion. Biol Reprod 63:1383–1389CrossRefPubMedGoogle Scholar
  5. 5.
    Aalkjaer C, Boedtkjer D, Matchov V (2011) Vasomotion – what is currently thought? Acta Physiol 202:253–269CrossRefGoogle Scholar
  6. 6.
    Aksenov D et al (2012) Effect of isoflurane on brain tissue oxygen tension and cerebral autoregulation in rabbits. Neurosci Lett 524(2):116–118CrossRefPubMedGoogle Scholar
  7. 7.
    Hasibeder W, Germann R, Sparr H et al (1994) Vasomotion induces regular major oscillations in jejunal mucosal tissue oxygenation. Am J Physiol 266:G978–G986PubMedGoogle Scholar
  8. 8.
    Bertuglia S et al (1991) Hypoxia- or hyperoxia-induced changes in arteriolar vasomotion in skeletal muscle microcirculation. Am J Physiol 260:H362–H372PubMedGoogle Scholar
  9. 9.
    Goldman D, Popel AS (2001) A computational study of the effect of vasomotion on oxygen transport in capillary networks. J Theor Biol 209:189–199CrossRefPubMedGoogle Scholar
  10. 10.
    Tsai AG, Intaglietta M (1993) Evidence of flowmotion induced changes in local tissue oxygen tension. Int J Microcirc Clin Exp 12:75–88PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, New York 2016

Authors and Affiliations

  • Robert A. Linsenmeier
    • 1
    • 2
    • 3
    Email author
  • Daniil P. Aksenov
    • 4
  • Holden M. Faber
    • 1
    • 5
  • Peter Makar
    • 1
  • Alice M. Wyrwicz
    • 1
    • 4
  1. 1.Department of Biomedical EngineeringNorthwestern UniversityEvanstonUSA
  2. 2.Department of NeurobiologyNorthwestern UniversityEvanstonUSA
  3. 3.Department of OphthalmologyNorthwestern UniversityChicagoUSA
  4. 4.NorthShore University HealthSystemEvanstonUSA
  5. 5.Department of Engineering Sciences and Applied MathematicsNorthwestern UniversityEvanstonUSA

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