Fig. 3

Effects of phenytoin on hippocampal epileptiform activities. Extracellular field potentials recorded from two thick slices (A–E) and one thin slice (G–I) of young mice. Spontaneous (A–E) or high frequency stimulation (HFS)-induced discharge (G–I) collected during slice perfusion with moderately modified (m)ACSF. Phenytoin added in mACSF at indicated concentrations and application times denoted by solid lines above traces. A Spontaneous CA3 field potentials recorded before and following phenytoin application and illustrated after treatment with a band-pass filter (2–500 Hz). B, C arrowed events expanded in a wide frequency band (0–1000 Hz). Filled circles in B denote preictal spikes. D–F and G–I, CA3 field potentials similarly illustrated as above. Note discharges with the hypersynchronous onset in B and E and the discharge without an evident component of the hypersynchronous onset in H