Fig. 9.
Mean responses of field potentials as a function of measured PmO2 at normobaric pressure (NBO) and HBO. Mean responses of oPS, fEPSP, and aPS are plotted as a function of PmO2. The oPS data are reproduced from Fig. 9A in the first of the companion articles (9). Multiple measures of CA1 neuronal excitability indicate that hippocampal slices maintained in normobaric hyperoxia (0.95 ATA O2) exhibit their greatest O2 sensitivity in the range of normobaric oxygenation (NBO: oPS, fEPSP, and aPS). In contrast, O2 sensitivity of the mechanisms underlying the aPS and fEPSP plateaus are saturated beginning at 0.95 ATA O2. Likewise, the O2 sensitivity of the oPS is significantly reduced beginning at 0.95 ATA O2 and above (see Ref. 9 for statistics).