Functional connectivity during epileptogenesis

Epilepsy is one of the most serious neurological diseases, affecting 1% of the world population. The disease is characterized by recurrent and spontaneous seizures due to the abnormal excessive activity of the neurons in the brain. The transition from a normal brain to a brain generating seizures, a process called epileptogenesis, is still unclear. For this reason, we explored the dynamics of the brain activity before and after a lesion with kainic acid in rats. This lesion causes rats to develop epilepsy and present spontaneous seizures within the next few months. More specifically, we explored the functional connectivity of the brain network before, one day and seven days after the lesion. Four different methods of functional connectivity were compared, two proposed and two classical methods. The proposed methods performed better than others. We observed a decrease of connectivity of the entorhinal cortex, a connecting bridge between the hippocampus and the neocortex, after the lesion. An increase of connectivity within the hippocampus and neocortex was also observed. We confirmed that the brain networks change during epileptogenesis, making the brain prone to present epileptic seizures.