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ISSN 2522-9028 (Print)
ISSN 2522-9036 (Online)
DOI: https://doi.org/10.15407/fz

Fiziologichnyi Zhurnal

is a scientific journal issued by the

Bogomoletz Institute of Physiology
National Academy of Sciences of Ukraine

Editor-in-chief: V.F. Sagach

The journal was founded in 1955 as
1955 – 1977 "Fiziolohichnyi zhurnal" (ISSN 0015 – 3311)
1978 – 1993 "Fiziologicheskii zhurnal" (ISSN 0201 – 8489)
1994 – 2016 "Fiziolohichnyi zhurnal" (ISSN 0201 – 8489)
2017 – "Fiziolohichnyi zhurnal" (ISSN 2522-9028)

Fiziol. Zh. 2016; 62(4): 3-11


Modulation of 4-aminopyridine-induced neuronal activity and local pO2 in rat hippocampal slices by changing the flow rate of the superfusion medium

V.G. Sydorenko, O.S. Komarov, B.S. Sushko, A.K. Romanov, E.V. Isaeva, D.S. Isaev

    O. O. Bogomoletz Institute of Physiology, National Academy of Science, Ukraine, Kyiv
DOI: https://doi.org/10.15407/fz62.04.003

Abstract

The brain slice preparation is the most frequently used tool for testing of pharmacological agents on the neuronal excitability. However, in the absence of blood circulation in vitro, the tissue oxygenation strongly depends on the experimental conditions. It is well established that both hypoxia as well as hyperoxia can modulate the neuronal network activity. Thereby changes in tissue oxygen level during experiment may affect the final result. In the present study we investigated the effect of oxygenation on seizure susceptibility in the hippocampal slice preparation using 4-aminopyridine (4-AP) model of ictogenesis in immature rats. We found that changing the medium perfusion rate in the range of 1-5 ml/min greatly affects the tissue oxygenation, amplitude and frequency of 4-AP-induced synchronous neuronal activity. The decrease in the flow rate as well as substitution of the oxygen in the extracellular medium with nitrogen causes a strong reduction of 4-AP-induced synchronous neuronal discharges. Our results demonstrate a significant linear correlation between the power of 4-AP-induced neuronal activity and the oxygen level in slice tissue. Also we demonstrated that the presence of medium flow is a necessary condition to support the constant level of the slice oxygenation. These data suggest that the oxygen supply of the brain slice strongly depends on experimental protocol and could modulate in vitro neuronal network excitability which should be taken into consideration when planning epilepsy-related studies.

Keywords: brain slices; synchronous neuronal activity; oxygen; local field potential

References

  1. Yamamoto C, McIlwain H. Electrical activities in thin sections from the mammalian brain maintained in chemically-defined media in vitro. J Neurochem. 1966 Dec;13(12):1333–43. CrossRef PubMed
  2.  
  3. Isaeva E, Lushnikova I, Savrasova A, Skibo G, Holmes GL, Isaev D. Blockade of endogenous neuraminidase leads to an increase of neuronal excitability and activitydependent synaptogenesis in the rat hippocampus. Eur J Neurosci. 2010 Dec;32(11):1889–96. CrossRef PubMed
  4.  
  5. Isaeva E, Romanov A, Holmes GL, Isaev D. Status epilepticus results in region-specific alterations in seizure susceptibility along the hippocampal longitudinal axis. Epilepsy Res. 2015 Feb;110:166–70. CrossRef PubMed PubMedCentral
  6.  
  7. Vanzetta I, Grinvald A. Increased cortical oxidative metabolism due to sensory stimulation: implications for functional brain imaging. Science. 1999;286(5444):1555–8. CrossRef PubMed
  8.  
  9. Foster KA, Beaver CJ, Turner DA. Interaction between tissue oxygen tension and NADH imaging during synaptic stimulation and hypoxia in rat hippocampal slices. Neuroscience. 2005;132(3):645–57. CrossRef PubMed
  10.  
  11. Turner DA, Foster KA, Galeffi F, Somjen GG. Differences in O2 availability resolve the apparent discrepancies in metabolic intrinsic optical signals in vivo and in vitro. Trends Neurosci. 2007;30(8):390–8. CrossRef PubMed PubMedCentral
  12.  
  13. Kann O, Huchzermeyer C, Kovács R, Wirtz S, Schuelke M. Gamma oscillations in the hippocampus require high complex i gene expression and strong functional performance of mitochondria. Brain. 2011;134(2):345–58. CrossRef PubMed
  14.  
  15. Ivanov A and Zilberter Y. Critical state of energy metabolism in brain slices: the principal role of oxygen delivery and energy substrates in shaping neuronal activity. Front Neuroenergetics. 2013;3:1-13.
  16.  
  17. Dzhala V, Khalilov I, Ben-Ari Y, Khazipov R. Neuronal mechanisms of the anoxia-induced network oscillations in the rat hippocampus in vitro. J Physiol. 2001;536(2):521–31. CrossRef PubMed PubMedCentral
  18.  
  19. Jensen FE, Applegate CD, Holtzman D, Belin TR, Burchfiel JL. Epileptogenic effect of hypoxia in the immature rodent brain. Ann Neurol. 1991;29(6):629–37. CrossRef PubMed
  20.  
  21. Galeffi F, Somjen GG, Foster KA, Turner DA. Simultaneous monitoring of tissue PO2 and NADH fluorescence during synaptic stimulation and spreading depression reveals a transient dissociation between oxygen utilization and mitochondrial redox state in rat hippocampal slices. J Cereb Blood Flow Metab. 2011;31(2):626–39. CrossRef PubMed PubMedCentral
  22.  
  23. Masamoto K, Omura T, Takizawa N, Kobayashi H, Katura T, Maki A, et al. Biphasic changes in tissue partial pressure of oxygen closely related to localized neural activity in guinea pig auditory cortex. J Cereb Blood Flow Metab. 2003;23(9):1075–84. CrossRef PubMed
  24.  
  25. Mulkey DK, Henderson R a, Olson JE, Putnam RW, Dean JB. Oxygen measurements in brain stem slices exposed to normobaric hyperoxia and hyperbaric oxygen. J Appl Physiol. 2001;90(5):1887–99. PubMed
  26.  
  27. Huxley VH, Kutchai H. The effect of the red cell membrane and a diffusion boundary layer on the rate of oxygen uptake by human erythrocytes. J Physiol. 1981;316:75–83. CrossRef  
  28. Bassom AP, Ilchmann A, Voss H. Oxygen diffusion in tissue preparations with Michaelis-Menten kinetics. J Theor Biol. 1997;185(1):119–27. CrossRef PubMed
  29.  
  30. Furukawa K, Yamana K, Kogure K. Postischemic alterations of spontaneous activities in rat hippocampal CA1 neurons. Brain Res. 1990;530(2):257–60. CrossRef  
  31. Gao TM, Xu ZC. In vivo intracellular demonstration of an ischemia-induced postsynaptic potential from CA1 pyramidal neurons in rat hippocampus. Neuroscience. 1996;75(3):665–9. CrossRef  
  32. Garcia AJ, Putnam RW, Dean JB. Hyperbaric hyperoxia and normobaric reoxygenation increase excitability and activate oxygen-induced potentiation in CA1 hippocampal neurons. J Appl Physiol. 2010;109(3):804–19. CrossRef PubMed PubMedCentral
  33.  
  34. Simon AJ, Torbati D. Effects of hyperbaric oxygen on heart, brain, and lung functions in rat. Undersea Biomed Res. 1982;9(3):263–75. PubMed
  35.  
  36. Torbati D, Mokashi A, Lahiri S. Effects of acute hyperbaric oxygenation on respiratory control in cats. J Appl Physiol. 1989;67(6):2351–6. PubMed
  37.  

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