Fig. 6.

The effects of 200 μm theophylline on simultaneously recorded intracellular EPSCs and extracellular field excitatory postsynaptic potentials (fEPSPs). A, The ensemble average response (mean ± SEM) induced by application of 200 μm theophylline for the EPSC recorded from control cells (•; n = 5) or 5 mmadenosine-loaded cells (○; n = 5). The duration of theophylline application is indicated by the horizontal bar at the bottom of the graph. B, The concurrent change in the fEPSP (mean ± SEM) when simultaneous whole-cell recording was conducted with control solution (•;n = 5 slices) or electrode solution containing 5 mm adenosine (○; n = 5 slices).C, D, The effect of 200 μmtheophylline on the EPSC (C) from a cell recorded with an adenosine-free electrode solution and the corresponding fEPSP responses (D). The smaller response in each case is the pre-drug control, and the larger response is during theophylline superfusion. The tracings are averages of 8–12 sweeps.E, F, Corresponding responses from a cell recorded with an electrode solution containing 5 mmadenosine (E) and the corresponding fEPSP responses (F). In both cases, the larger response was recorded in the presence of 200 μm theophylline.