title: The anti-ictogenic effects of levetiracetam are mirrored by interictal spiking and high-frequency oscillation changes in a model of temporal lobe epilepsy.
abstract: OBJECTIVE
  Mesial temporal lobe epilepsy (MTLE) is the most prevalent type of partial epileptic disorders. In this study, we have analyzed the impact of levetiracetam (LEV) in the pilocarpine model of MTLE.
  
  
  METHODS
  Sprague-Dawley rats (n=19) were injected with pilocarpine (380 mg/kg, i.p.) to induce a status epilepticus. Twelve animals were used as controls and seven were treated with LEV. They were implanted with bipolar electrodes in the CA3 subfield of the hippocampus, entorhinal cortex (EC), dentate gyrus (DG) and subiculum and EEG-video monitored continuously from day 4 to day 14 after SE.
  
  
  RESULTS
  Only 29% of LEV-treated animals had seizures compared to all controls following a latent period that was similar in duration. Seizure rates were lower in LEV-treated animals. In LEV-treated animals without seizures, lower interictal spike rates were found in all regions compared to controls. Analysis of interictal high-frequency oscillations (HFO s) revealed that LEV-treated animals without seizures had lower rates of interictal spikes with ripples (80-200 Hz) in CA3, EC and subiculum (p<0.01), whereas rates of interictal spikes with fast ripples (250-500 Hz) were significantly lower in CA3 and subiculum, compared to controls.
  
  
  CONCLUSIONS
  Our findings indicate that the anti-ictogenic properties of LEV are mirrored by decreases of interictal spike rate in temporal lobe regions, and are accompanied by subregion-specific decreases of HFO occurrence in CA3 and subiculum. Overall, this evidence suggest that LEV may inhibit neural network activity in regions that are known to play important roles in MTLE.
authors: Montreal Neurological Institute and Department of Neurology & Neurosurgery, McGill University, Montréal, Qc H3A 2B4, Canada.
authors: Maxime
authors: M
authors: Lévesque
authors: Montreal Neurological Institute and Department of Neurology & Neurosurgery, McGill University, Montréal, Qc H3A 2B4, Canada.
authors: Charles
authors: C
authors: Behr
authors: Montreal Neurological Institute and Department of Neurology & Neurosurgery, McGill University, Montréal, Qc H3A 2B4, Canada. Electronic address: massimo.avoli@mcgill.ca.
authors: Massimo
authors: M
authors: Avoli
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D004195:Disease Models, Animal; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000188:drug therapy* / Q000503:physiopathology*; D006624:Hippocampus / Q000187:drug effects* / Q000503:physiopathology*; D000077287:Levetiracetam; D008297:Male; D010507:Periodicity; D010862:Pilocarpine; D010889:Piracetam / Q000031:analogs & derivatives* / Q000494:pharmacology; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000188:drug therapy / Q000503:physiopathology; D016896:Treatment Outcome; D014741:Video Recording
chemical_list: D000927:Anticonvulsants; D010862:Pilocarpine; D000077287:Levetiracetam; D010889:Piracetam
keywords: High-frequency oscillations; Interictal spikes; Levetiracetam; Pilocarpine; Seizures
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