KA insult has a regionalized impact on excitability within the hippocampal slice culture. (A) Rhythmic synchronized neuronal events typically seen under Mg2+-free conditions. Activity is clearly evident in both CA1 and CA3 regions. (B) 24 hours following a KA insult, synchronized neuronal events are only recorded in the CA1 region. (C) Proportion of hippocampal slices showing CA3 firing 24 hours following KA insult, (* p < 0.05, n = 19, χ2 test).