Stimulus-induced Epileptic Spike-Wave Discharges in Thalamocortical Model with Disinhibition.

Denggui Fan,Suyu Liu,Qingyun Wang

doi:10.1038/srep37703

Denggui Fan, Suyu Liu + Show 1 more

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https://doi.org/10.1038/srep37703

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Abstract

Epileptic absence seizure characterized by the typical 2–4 Hz spike-wave discharges (SWD) are known to arise due to the physiologically abnormal interactions within the thalamocortical network. By introducing a second inhibitory neuronal population in the cortical system, here we propose a modified thalamocortical field model to mathematically describe the occurrences and transitions of SWD under the mutual functions between cortex and thalamus, as well as the disinhibitory modulations of SWD mediated by the two different inhibitory interneuronal populations. We first show that stimulation can induce the recurrent seizures of SWD in the modified model. Also, we demonstrate the existence of various types of firing states including the SWD. Moreover, we can identify the bistable parametric regions where the SWD can be both induced and terminated by stimulation perturbations applied in the background resting state. Interestingly, in the absence of stimulation disinhibitory functions between the two different interneuronal populations can also both initiate and abate the SWD, which suggests that the mechanism of disinhibition is comparable to the effect of stimulation in initiating and terminating the epileptic SWD. Hopefully, the obtained results can provide theoretical evidences in exploring dynamical mechanism of epileptic seizures.

Highlights

~2–4 Hz spike-wave discharge (SWD) discharges of absence seizure can be benign due to the transient deprivation of consciousness[20]
It has been confirmed that the competing mechanisms among different neuronal populations can lead to robust periodic SWD discharges dynamics[57] when they operate on the different timescales mediated by the inhibitory GABAA and GABAB receptors, respectively
We investigate the effects of stimulus perturbations on the occurrence of SWD discharges and its transition dynamics under the mutual functions between cortex and thalamus

Summary

Introduction

~2–4 Hz SWD discharges of absence seizure can be benign due to the transient deprivation of consciousness[20]. Stimulus perturbations can control or suppress the epileptic seizures 20,24–34, which can offer a potential alternative to the traditional therapy with antiepileptic drugs Both the epileptic humans and animal models, as well as the theoretical model[20], have been conducted to investigate the feasibility of stimulation for aborting brain activities related to the absence seizures with SWD discharges[35]. A thalamocortical model (see Fig. 1(a)) has been developed to investigate stimulus driven epileptic seizure abatement[20,54] Whereas, in this thalamocortical model disinhibition functions among different inhibitory neuronal populations have not been mentioned[40,55]. We further study the control effect of disinhibition on the stimulus-induced SWD discharges

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