Changes in network dynamics during status epilepticus

Status epilepticus (SE) is an acute event, characterized by repeated or continuous seizures, which alters neuronal properties of the brain and can promote the epileptic disorder. Experimental observations indicate that SE becomes progressively less responsive to anti-epileptic drugs, suggesting changes in the underlying physiology. To assess the effect of SE on neuronal dynamics as it progresses, we measured changes in neuronal activity from CA3 hippocampus, ipsilateral and contralateral to a focal intrahippocampal injection of kainic acid during the full course of SE, 24 h post-SE, and one week post-SE. The progressively intensifying behavioral response during SE was accompanied by changes in intrinsic firing properties of single neurons, LFP oscillations and interaction between single neurons and the oscillations. These results show important changes in neuronal and network activity underlying the progression of SE.