Electrophysiological verifications of implanted electrodes. A, representative field potentials collected from a mouse at the beginning the kindling procedure (gray) and after reaching a fully kindled state (black). These field potentials were evoked by unilateral hippocampal CA3 stimulation (arrowed) and recorded from the contralateral CA3 area. Each illustrated trace was averaged from 5 consecutive responses. The artifact of the stimulation is indicated (arrow). B, the amplitudes of CA3 field potentials measured from 5 animals pre-kindling (gray) and after kindled (black). *, initial vs. kindled responses; p < 0.05, paired t test. C, interictal-like hippocampal spikes (arrowed) recorded from a kindled animal. D, incidences of hippocampal spikes measured pre-kindling and after fully kindled. *, p = 0.013, paired t-test, n = 7. E-F, representative spectral plots were generated from EEG signals that were recorded from an animal (G) pre-kindling (E) and after fully kindled (F). The spectral plots were generated from EEG segments of 30-second or 5-second during wake immobile (black) or exploratory (gray) behavior. Power was normalized to the peak of the delta band (0.5-4 Hz). G, representative EEG traces collected from the same animal after fully kindled. H, peak frequencies of hippocampal theta rhythms (5–12 Hz) and delta irregular activities (0.5-4 Hz) were measured from 7 animals. The peak frequencies of hippocampal theta and delta activities were not significantly altered in kindled animal relative to pre-kindling measurements (p = 0.723 and p = 0.524, paired test).
Jeffrey et al. BMC Neuroscience 2013 14:82 doi:10.1186/1471-2202-14-82