Fig. 4.

The effect of changes in oxygen partial pressure ($P_{{\text{O}}_2}$) on action potential frequency in the SLN. The bottom reading is a raw digitised recording, the middle trace is $P_{{\text{O}}_2}$ of the perfusate at a constant temperature of 37 °C. The top trace is the mean action potential frequency of a single unit (averaged over 10 s) extracted from the raw recording. The inset shows all superimposed action potentials of the discriminated single unit (window is 2 ms in duration). At the intervals indicated by horizontal bars increasing concentrations of sodium cyanide are administered to the glomi.