Gap junctions are involved in the maintenance of seizure-like activity.

<p>(A) In the 4-AP and bicuculline control group, seizure-like activity began to appear after 10 min and reached a maximum after 80 min (upper panel). The application of 100 µM CBX 30 min prior to the application of 4-AP and bicuculline did not delay the onset of seizure-like activity. However, in the CBX group, seizure-like activity was not potentiated (lower panel). (B) Statistical results of the changes in the duration and amplitude of seizure-like activity over time. The duration and amplitude in the 4-AP and bicuculline control group were significantly greater than in the CBX group after 50 min of seizure induction. (C) The statistical results showed that CBX did not significantly influence the initial phase, but CBX could significantly decreased the duration and amplitude of seizure-like activity in the maintenance phase. (D) Time-lapse recording of potassium concentration. (E) Development of seizure-like activity. The potassium concentration increased before seizure-like activity turned into a longer duration. (F) Statistical results of time-lapse recording of potassium concentration. The application of 4-AP and bicuculline significantly increased potassium concentration, whereas the application of CBX significantly decreased it. (G) The duration of seizure-like activity was positively correlated with the concentration of extracellular potassium ions.