TITLE:
Hippocampal High-Frequency Stimulation Inhibites the Progression of Rapid Kindling-Induced Seizure in Rats
AUTHORS:
Belen Gori, Magdalena Pereyra, Lucas Toibaro, Carola Brescacin, Gerardo Battaglia, Julieta Pastorino, Ariela Smigliani, Milagros Galardi, Silvia Kochen
KEYWORDS:
Hippocampal Rapid Kindling; Epilepsy; Electrical Stimulation; High-Frequency Stimulation; Low-Frequency Stimulation
JOURNAL NAME:
Neuroscience and Medicine,
Vol.4 No.2,
June
7,
2013
ABSTRACT: Epilepsy is one of the
most common serious neurological disorders. Pharmacoresistant epilepsy patients
are poorly controlled or their seizures are refractory to drug treatment.
Resective surgery is frequently a promising therapy in this population,
however, not all the patients meet the eligibility criteria for the surgical
treatment. Deep brain stimulation has
been investigated in clinical studies and animal studies as an alternative
treatment, but the optimal stimulation parameters remain an issue. The present study was designed to investigate the effect of unilateral high-frequency stimulation (HFS) of
hippocampus on seizure development by using the hippocampal rapid kindling
method (hRK) in rats, and compared the results with those of low-frequency stimulation previously published by
our group. We used male Wistar rats implanted with electrodes in the ventral
hippocampus. All rats underwent hRK (biphasic square wave pulses, 20 Hz for 10
seconds) during three consecutive days (twelve stimulations per day). The
control group (hRK; n = 7) received only RK stimulus, while
the treated group (HFS-hRK; n = 9) received also
HFS (biphasic square wave pulses, 130 Hz for 30 seconds) immediately before the
RK stimulus, during three consecutive days. At the end of behavioral testing
78% (p 0.01) of the animals receiving HFS
treatment were still not fully kindled staying in stages 0 -III (p 0.01). HFS group needed a higher
number of stimulations to achieve stage III (p 0.05) with respect to control group.
However, no
significant differences in the cumulative daily afterdischarge duration were
observed. HFS did not present significant differences compared with LFS in any of studied parameters. The findings suggest that unilateral HFS applied on hippocampus
effectively inhibited the epileptogenic process induced by hippocampal rapid
kindling. According to the comparative results about hippocampal rapid kindled
animals stimulated with HFS and LFS (5 Hz), we found no conclusive information on which treatment is most
efficient.