Fast Fourier transformation analysis of kindling-induced afterdischarge in the rabbit hippocampus

Tsuchiya, Komei; Kogure, Shinichi

doi:10.1016/j.eplepsyres.2011.03.015

Cited by 13 publications

(11 citation statements)

References 32 publications

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“…We identify the ADs as high amplitude EEG waves (i.e., ≥750 μV peak to peak) that appear in the form of spikes trains and spike-waves most of them between 1–8 Hz, and lasting for at least 5 s (Lothman et al, 1985; Musto et al, 2009; Tsuchiya and Kogure, 2011). In both RK and SK groups, the AD threshold, described as the minimum current intensity needed to evoke an AD in any recording channel; was determined for each rat.…”

Section: Methodsmentioning

confidence: 99%

“…EEG activity induced in the stimulated structure—namely afterdischarge (AD)—has been correlated with an increase in synchronous activity and hyperexcitability of a large group of neurons (Taylor and Dudek, 1982). The protocol progression is assessed through a behavioral scale known as “Racine Stages” (Racine, 1972b), which can be directly correlated with the AD duration and EEG frequency bands (Musto et al, 2009; Tsuchiya and Kogure, 2011). …”

Section: Introductionmentioning

confidence: 99%

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A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats

Morales

Álvarez-Ferradas

Roncagliolo

et al. 2014

Front. Cell. Neurosci.

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Kindling, one of the most used models of experimental epilepsy is based on daily electrical stimulation in several brain structures. Unlike the classic or slow kindling protocols (SK), the rapid kindling types (RK) described until now require continuous stimulation at suprathreshold intensities applied directly to the same brain structure used for subsequent electrophysiological and immunohistochemical studies, usually the hippocampus. However, the cellular changes observed in these rapid protocols, such as astrogliosis and neuronal loss, could be due to experimental manipulation more than to epileptogenesis-related alterations. Here, we developed a new RK protocol in order to generate an improved model of temporal lobe epilepsy (TLE) which allows gradual progression of the epilepsy as well as obtaining an epileptic hippocampus, thus avoiding direct surgical manipulation and electric stimulation over this structure. This new protocol consists of basolateral amygdala (BLA) stimulation with 10 trains of biphasic pulses (10 s; 50 Hz) per day with 20 min-intervals, during 3 consecutive days, using a subconvulsive and subthreshold intensity, which guarantees tissue integrity. The progression of epileptic activity was evaluated in freely moving rats through electroencephalographic (EEG) recordings from cortex and amygdala, accompanied with synchronized video recordings. Moreover, we assessed the effectiveness of RK protocol and the establishment of epilepsy by evaluating cellular alterations of hippocampal slices from kindled rats. RK protocol induced convulsive states similar to SK protocols but in 3 days, with persistently lowered threshold to seizure induction and epileptogenic-dependent cellular changes in amygdala projection areas. We concluded that this novel RK protocol introduces a new variant of the chronic epileptogenesis models in freely moving rats, which is faster, highly reproducible and causes minimum cell damage with respect to that observed in other experimental models of epilepsy.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats

Morales

Álvarez-Ferradas

Roncagliolo

et al. 2014

Front. Cell. Neurosci.

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“…Theses waves are also augmented in generalization of epileptic seizures. Moreover, suppression of beta and gamma frequencies can inhibit the progression of epileptogenesis process ( Tsuchiya and Kogure, 2011 ). In addition to the above sub-bands, alterations of theta/alpha ratio have shown a significant correlation with the level of alertness in cognitive studies ( Sadighi Alvandi et al, 2015 ) because theta sub-bands are usually correlated with learning and alertness disorders, and they are often emerged with high amplitude in the epileptic patients while alpha frequencies are generally the most stable brain waves.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Analysis of the Antiepileptogenic Effects of Low Frequency Stimulation Applied Prior or After Kindling Stimulation in Rats

et al. 2018

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Background and Objective: Developing quantitative measures based on spectral analysis of electroencephalograph (EEG) recordings of neural activities plays an important role in developing efficient treatments for epilepsy. Such biomarkers can be used for developing open or closed loop approaches for seizure prediction or prevention. This study aims to quantitatively evaluate antiepileptogenic effects of low frequency stimulation (LFS) applied immediately before or after kindling stimulations using spectral power analysis of extracellular EEG in rat.Methods: Nineteen adult rats were used: seven for kindle, six for LFS+Kindle (LFSK) and six for Kindle+LFS (KLFS). Four packages of LFS (1Hz) were applied immediately before or after rapid kindling stimulations. The power spectral densities of afterdischarge (AD) sections of EEG corresponding to different stages of kindling for delta (0–4 Hz), theta (4–8 Hz), alpha (8–12 Hz), beta (12–28 Hz), gamma (28–40 Hz) sub-bands, and theta/alpha ratio were comparatively investigated. Moreover, correlation between AD duration (ADD) and its different frequency components was calculated.Results: Both LFSK and KLFS significantly increased delta and reduced beta and gamma oscillations, compared with kindle group. However, just the reduction in LFSK group was significant. Both protocols increased theta/alpha ratio, but just LFSK showed significant increase (p < 0.05). Although LFSK enhanced theta/alpha ratio more than KLFS, the difference was not statistically significant. Furthermore, strong correlation between each frequency sub band and ADD was not observed in kindle and LFS treated groups (both LFSK and KLFS).Conclusion: Although behavioral assessments showed relatively the same level of antiepileptogenic effects for KLFS and LFSK, quantitative assessments showed more significant differences in the quantitative measures between the two protocols. Developing more quantitative EEG based measures correlated with LFS-induced effects can facilitate developing open or closed loop seizure prevention modalities.

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“…The raw LFP signal is a complex waveform which shows temporal variations in multiple domains, including amplitude, frequency, and phase. Fourier analysis isolates individual components of a compound waveform, and has been used to describe various aspects of the electrical seizure signal (Bronzino, 1984 ; Hilfiker and Egli, 1992 ; Blanke et al, 2000 ; Onoe and Nishigaki, 2004 ; Tsuchiya and Kogure, 2011 ). To analyze ictal activity beyond the standard measures of duration and total power, we also performed FFT analyses for cross power spectrum and coherence, which are additional means of analyzing the relationship between Fourier-transformed domains of the underlying electrical waveform (Bronzino, 1984 ; Davey et al, 2000 ).…”

Section: Resultsmentioning

confidence: 99%

Reduction in focal ictal activity following transplantation of MGE interneurons requires expression of the GABAA receptor Î±4 subunit

Jaiswal

Keros

Zhao

et al. 2015

Front. Cell. Neurosci.

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Despite numerous advances, treatment-resistant seizures remain an important problem. Loss of neuronal inhibition is present in a variety of epilepsy models and is suggested as a mechanism for increased excitability, leading to the proposal that grafting inhibitory interneurons into seizure foci might relieve refractory seizures. Indeed, transplanted medial ganglionic eminence interneuron progenitors (MGE-IPs) mature into GABAergic interneurons that increase GABA release onto cortical pyramidal neurons, and this inhibition is associated with reduced seizure activity. An obvious conclusion is that inhibitory coupling between the new interneurons and pyramidal cells underlies this effect. We hypothesized that the primary mechanism for the seizure-limiting effects following MGE-IP transplantation is the tonic conductance that results from activation of extrasynaptic GABAA receptors (GABAA-Rs) expressed on cortical pyramidal cells. Using in vitro and in vivo recording techniques, we demonstrate that GABAA-R α4 subunit deletion abolishes tonic currents (Itonic) in cortical pyramidal cells and leads to a failure of MGE-IP transplantation to attenuate cortical seizure propagation. These observations should influence how the field proceeds with respect to the further development of therapeutic neuronal transplants (and possibly pharmacological treatments).

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Fast Fourier transformation analysis of kindling-induced afterdischarge in the rabbit hippocampus

Cited by 13 publications

References 32 publications

A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats

A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats

Quantitative Analysis of the Antiepileptogenic Effects of Low Frequency Stimulation Applied Prior or After Kindling Stimulation in Rats

Reduction in focal ictal activity following transplantation of MGE interneurons requires expression of the GABAA receptor Î±4 subunit

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