Comparisons of different seizure models in the callosal slice preparation using dual recordings in two hemispheres simultaneously.

<p>Representative examples of bilateral EEs recorded in BIC (<b>Ai</b> and <b>Aii</b>) versus 0Mg (<b>Bi</b> and <b>Bii</b>) are shown. In each bilateral EE example, there are two simultaneous recordings, where each recording is gathered from opposite hemispheres in a single slice preparation. <b><i>Ai</i></b> and <b><i>Bi</i></b> show events that resemble inter-ictal events (5 sec. or less). These were the predominant kind of events recorded overall, and the only kind of event recorded in the BIC recordings. <b><i>Aii</i></b> and <b><i>Bii</i></b> show the longest event recorded for BIC (approx. 5 sec.), and a typical ictal-like event for 0Mg (approx. 30 sec.), respectively (note differerent time scales in the <b><i>i</i></b> vs. <b><i>ii</i></b> panels). For all panels, 0.4 mV is the y-scale for BIC, while 0.1 mV represents the y-scale for 0Mg, reflecting the significantly larger amplitudes found for these EEs in BIC. (<b>Aiii</b>) Significant differences in the number of EEs arise between the BIC and BIC+MK801 groups during the course of recordings (Wilcoxon rank sum test). (<b>Aiv</b>) The proportion of EEs that are unilateral decreases more in the BIC group than in the BIC+MK801 group (Chi square test of proportions). Data from both (<b>Aiii</b>) and (<b>Aiv</b>) show mean ± SE. n = 17 paired recordings from 17 slices from 9 mice in the BIC group, while n = 17 paired recordings from 17 slices from 5 mice in the BIC+MK801 group. (<b>Biii</b>) The number of EEs increase during long recordings in 0Mg. Data shown are only from slices that demonstrated any EEs during recordings (n = 27 from a total of 46 slices). (<b>Biv</b>) In contrast to BIC data, there is not a significant decrease in the proportion of unilateral events during long recordings. Data shown are only from slices that demonstrated at least one bilateral EE (n = 13 slices).