Associating sensory cues with incoming seizures: developing an animal model of auras

Abstract

For patients with epilepsy, one of the biggest problems is the unpredictability of the time when the next seizure will occur. Interestingly, some epileptic patients experience a sensory sensation preceding seizures, called aura, which helps them move to safety before a seizure. Here, we describe the development of the first animal model of auras, which could allow for a more detailed study of this phenomenon. Specifically, in mice, we presented sensory stimuli (sound and light cues) a few seconds before kindling an animal to induce seizures. Animals were kindled by electrical stimulation in the basolateral amygdalar nucleus. Over the course of stimulation sessions, animals started showing progressively stronger freezing behavior to sensory cues preceding kindling. Interestingly, seizures are known to cause retrograde amnesia, thus it was surprising that the association between seizures and preceding sensory cues developed in all experimental animals. In summary, our experiments show that similarly to auras, a sensory sensation can be associated with incoming generalized seizures and is not erased by retrograde amnesia.