A Link between Vasomotion and Spontaneous Oscillations of Oxygen in Rat Brain

Abstract

Early recordings with oxygen electrodes show that under steady state conditions, tissue oxygen tension (Po₂) undergoes spontaneous fluctuations (Clark, 1958; Cooper et al., 1966; Hardwick, 1996; Misrahy et al, 1962). These oscillations differ between organs and species but a general pattern of l–10c/min with an amplitude of 10–30% of the mean Po₂ has been observed (Morita-Tsuzuki et al., 1992; Hasibeder et al., 1994; Braun et al., 1992; Eickhoff and Jacobsen, 1982; Towell et al., 1976; Manil et al., 1984). Recordings of oscillations in flowmotion by other methods such as laser Doppler and magnetic resonance imaging (MRI) (Beinder et al, 1994; Morita-Tsuzuki et al., 1992; Hudetz et al., 1992; Biswal and Hudetz, 1996; Ren et al., 1993; Biswal et al., 1995, 1996) appear to exhibit similar frequencies of oscillation as the Po₂.