Figure 6. Field recordings of evoked excitatory postsynaptic potentials (EPSPs) and fiber volleys showing that EPSP depression occurred with a decrease in fiber volley amplitude. Traces shown are for control, 5.0 micro Meter riluzole, and an overlay for comparison. Bottom trace is an expanded view of the overlay's early portion, to highlight the decrease in fiber volley amplitude with 5.0 micro Meter riluzole (solid line) compared with control (dotted line).