Fig. 1.

Representative seizures induced by 4-aminopyridine (4AP) or picrotoxin. A: low-voltage fast (LVF) seizure recorded simultaneously from the CA3 region of hippocampus, the entorhinal cortex, and the subiculum in a rat 12 min after 4AP treatment. Insets show the onset of the seizure that is characterized by the occurrence of a spike followed by a low-voltage fast activity. B: hypersynchronous (HYP) seizure recorded simultaneously from the CA3 region of hippocampus, the entorhinal cortex, and the subiculum 30 min after picrotoxin treatment. Insets indicate the onset of the seizure and the expanded time scale of the periodic focal spikes at its onset. Bold lines on top of the traces represent the part of the seizure shown above with an expanded time scale.