Previous experiments in rats and epileptic brain regions in humans have shown that focal cooling consistently suppresses epileptic discharges without affecting the brain's normal neurological function. As such, this treatment shows potential for future development into an implantable cooling device.

The precise mechanisms by which focal cooling suppresses epileptic discharges, however, are still not clearly understood. In particular, focal cooling sometimes slightly increases the frequency of epileptic discharges in rats, even while suppressing their strength.

Now, a Japanese research team has used computer simulations to gain insight into how lowering the temperature of specific brain regions could potentially treat epileptic seizures. They employed a rat brain model that allowed them to simulate different mechanisms underlying the effects of a focal cooling device on epileptic discharges (PLoS Comput. Biol. 13 e1005736).

Based on data from laboratory and rat studies, Jaymar Soriano of Nara Institute of Science and Technology (NAIST) and colleagues used a neural mass model to reproduce epileptic discharge activity, simulating the effect of cooling by introducing temperature dependence into the model. They formulated two temperature-dependent mechanisms to reproduce the effect of cooling on epileptic discharge activity.

First, the researchers simulated a mechanism by which focal cooling reduces activity at connections between neurons, resulting in less frequent epileptic discharges. With this mechanism alone, however, the model could not accurately reproduce electrical activity patterns previously observed in brain cooling experiments on rats.

They then devised an intrinsic excitability mechanism that compensates for the reduction in frequency of discharges, resulting in discharges that were persistent during cooling but suppressed in magnitude. Incorporating both mechanisms into their model allowed the team to successfully reproduce results from the rat experiments.

"Focal brain cooling could be an alternative treatment for epileptic seizures with lower risk of irreversible functional loss compared to surgery," said co-author Takatomi Kubo from NAIST. "Our study attempts to start an initiative on thermal neuromodulation of brain activity using a computational approach that can elucidate its mechanism and complement animal experiments and clinical tests."