The impact of pathological high-frequency oscillations on hippocampal network activity in rats with chronic epilepsy

• DOI: 10.7554/elife.42148
• Publication Date: 2019-02-22T15:01:57Z
• Authors: Laura A Ewell; Kyle B Fischer; Christian Leibold; Stefan Leutgeb; Jill K Leutgeb
• Keywords: hippocampus; QH301-705.5; Science; 610; Action Potentials; pathological high frequency oscillations; Epilepsie; Hippocampus; memory; 03 medical and health sciences; 0302 clinical medicine; Memory; Animals; Biology (General); Epilepsy; Q; R; Electroencephalography; Rats; epilepsy; Medicine; place field; Nerve Net; Neuroscience

In epilepsy, brain networks generate pathological high-frequency oscillations (pHFOs) during interictal periods. To understand how pHFOs differ from normal in overlapping frequency bands and potentially perturb hippocampal processing, we performed high-density single unit local field potential recordings hippocampi of behaving rats with without chronic epilepsy. epileptic animals, observed two types co-occurring fast oscillations, which by comparison to control animals could classify as ‘ripple-like’ or ‘pHFO’. We compared their spectral characteristics, state dependence, cellular participants. Strikingly, pHFO occurred irrespective state, were associated spikes, engaged distinct subnetworks principal neurons ripple-like events, increased the sparsity network activity, initiated both general immediate disruptions spatial information coding. Taken together, our findings suggest that events result have an impact on memory processes, corroborating need for proper classification facilitate therapeutic interventions selectively target activity.