Epileptiform discharge progression from left neocortex in the pilocarpine epileptic rat model. (a) Non-EDs. The low amplitude, high frequency activity was firstly observed 1 - 5 min after pilocarpine treatment. (b) Continuous EDs. The prominent high amplitude spiking activity was seen and lasted up to 1~2 hours. (c) Periodic EDs. The bursting spike activity with pause was observed and ended gradually, and resumed to normalize EEG.