Brain State Is a Major Factor in Preseizure Hippocampal Network Activity and Influences Success of Seizure Intervention

• DOI: 10.1523/jneurosci.5112-14.2015
• Publication Date: 2015-11-25T17:37:45Z
• Authors: Laura A. Ewell; Liang Liang; Caren Armstrong; Ivan Soltész; Stefan Leutgeb; Jill K. Leutgeb
• Keywords: Male; 570; hippocampus; Wistar; 610; Action Potentials; interneuron; Hippocampus; 03 medical and health sciences; 0302 clinical medicine; Seizures; seizure prediction; Animals; Rats, Wistar; Neurons; Epilepsy; Electroencephalography; temporal lobe epilepsy; brain state; Temporal Lobe; Rats; Epilepsy, Temporal Lobe; REM sleep; Nerve Net

Neural dynamics preceding seizures are of interest because they may shed light on mechanisms seizure generation and could be predictive. In healthy animals, hippocampal network activity is shaped by behavioral brain state and, in epilepsy, selectively emerge during specific states. To determine the degree to which changes before pathological or reflect ongoing fluctuations state, dorsal neurons were recorded spontaneous a rat model temporal lobe epilepsy. Seizures emerged from all states, but with greater likelihood after REM sleep, potentially due an observed increase baseline excitability periods compared other brains states also characterized sustained theta oscillations. When comparing firing patterns same across associated without seizures, followed typical transitions, did not differ until onset electrographic seizure. Next, we tested whether disparate distinct would influence effectiveness optogenetic curtailment mouse Optogenetic was significantly more effective for preceded non-theta that Our results indicate consideration important appropriate interpretation leading up designing intervention. SIGNIFICANCE STATEMENT Hippocampal single-unit strongly yet this relationship has been largely ignored when studying medial increased attention using prediction closed-loop intervention, show need monitoring interpret correctly neural normal. Moreover, find determines success therapeutic interventions curtail duration. Together, these findings suggest intervention will successful if tailored emerge.