Spontaneous network minibursts recorded in hippocampal slices taken immediately after TTX cannula extraction. In this experiment, TTX infusion began on postnatal day 12, and slices were taken on postnatal day 26 as TTX was infused. A,Extracellular recordings from ACSF and TTX-infused animals.Trace 1, A slow time base extracellular field recording that demonstrates the lack of spontaneous network bursting in the CA3 cell body layer of an ACSF-infused animal. Trace 2,Spontaneous synchronized network minibursts from the CA3 cell body layer of a TTX-infused animal. A selected event (asterisk) in the slow time-based recordings intrace 2 is expanded in time in the inset. B, Plotted are the percentage of slices from dorsal through ventral hippocampus that showed spontaneous network minibursts. Slices were taken from the TTX-infused hippocampus of five rats.