Modulation of epileptiform discharges by heterogeneous interneurons and external stimulation strategies in the thalamocortical model

It is well known that inhibitory interneurons in the cerebral cortex can be classified as parvalbumin (PV), somatostatin subtypes (SOM), and vasoactive intestinal polypeptide subtypes (VIP) based on chemical characteristics. However, in models based on a corticothalamic model containing heterogeneous interneurons, the mechanisms underlying the dynamics of internal neurons and external stimuli are not well understood, and there are some challenges in selecting appropriate stimulation strategies. In this study, we first investigated and confirmed that insufficient feed-forward inhibition associated with PV neurons triggered seizures; second, we applied an optogenetic control strategy to confirm the control effect of excitatory optogenetic stimulation which targets either the PV or the SOM subtypes. Finally, we used a control strategy by applying both optogenetics and an electromagnetic induction stimulation to study the multiple possibilities of the dynamic evolution of seizures. The results confirmed that electromagnetic induction exhibits context-dependent effects in epileptic seizures, similar to the dual-effect phenomenon observed in previous studies, though with distinct network-level mechanisms in our thalamocortical model. In addition, a comparative analysis of the stimulation effects was performed. This work introduces a control scheme by combining internal neuronal pathways and external stimulation, thus providing new theoretical foundations and insights for the future treatment of epileptic seizures.