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Low frequency stimulation of ventral hippocampal commissures reduces seizures in a rat model of chronic temporal lobe epilepsy
Author(s) -
Rashid Saifur,
Pho Gerald,
Czigler Michael,
Werz Mary A.,
Durand Dominique M.
Publication year - 2012
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/j.1528-1167.2011.03348.x
Subject(s) - epilepsy , stimulation , hippocampal formation , temporal lobe , status epilepticus , ictal , hippocampus , anesthesia , medicine , hippocampal sclerosis , electroencephalography , psychiatry
Summary Purpose: To investigate the effects of low frequency stimulation (LFS) of a fiber tract for the suppression of spontaneous seizures in a rat model of human temporal lobe epilepsy. Methods: Stimulation electrodes were implanted into the ventral hippocampal commissure (VHC) in a rat post‐status epilepticus (SE) model of human temporal lobe epilepsy (n = 7). Two recording electrodes were placed in the CA3 regions bilaterally and neural data were recorded for a minimum of 6 weeks. LFS (60 min train of 1 Hz biphasic square wave pulses, each 0.1 ms in duration and 200 μA in amplitude, followed by 15 min of rest) was applied to the VHC for 2 weeks, 24 h a day. Key Findings: The baseline mean seizure frequency of the study animals was 3.7 seizures per day. The seizures were significantly reduced by the application of LFS in every animal (n = 7). By the end of the 2‐week period of stimulation, there was a significant, 90% (<1 seizure/day) reduction of seizure frequencies (p < 0.05) and a 57% reduction during the period following LFS (p < 0.05) when compared to baseline. LFS also resulted in a significant reduction of hippocampal interictal spike frequency (71%, p < 0.05), during 2 weeks of LFS session. The hippocampal histologic analysis showed no significant difference between rats that received LFS and SE induction and those that had received only SE‐induction. None of the animals showed any symptomatic hemorrhage, infection, or complication. Significance: Low frequency stimulation applied at a frequency of 1 Hz significantly reduced both the excitability of the neural tissue as well as the seizure frequency in a rat model of human temporal lobe epilepsy. The results support the hypothesis that LFS of fiber tracts can be an effective method for the suppression of spontaneous seizures in a temporal lobe model of epilepsy in rats and could lead to the development of a new therapeutic modality for human patients with temporal lobe epilepsy.