Spontaneous adenosine transients detected in lamina II by FSCV. (A-D) Concentration versus time traces (top) and color plots (bottom) in slices (lamina II) from (A) WT, (B) Pap-/-, (C) Nt5e-/-, and (D) dKO mice. Scale bars are for the 1.0 V traces. (A-inset) Cyclic voltammogram for the transient marked with an asterisk. Voltammograms had the signature shape for adenosine, as shown in Figure 3B. The abrupt vertical lines in the color plots are due to a change in double-layer capacitance when fast events occur at the electrode surface, as seen previously [56, 57].