Behavioral unresponsiveness and impaired auditory event-related potentials in the anterior insula during rat absence seizures.
bioRxiv : the preprint server for biology October 7, 2025 Stefan Sumsky, Rory Ashmeade, Jiayang Liu et al. preprint
Absence seizures cause sudden lapses in consciousness accompanied by spike-wave discharges, but how they impair sensory processing is unclear. In a rat model of absence epilepsy, behavioral performance on an auditory task collapsed during seizures, dropping from about 88% correct to less than 1%. However, electrical responses in the primary auditory cortex remained normal. Instead, a novel oscillatory signal in the anterior insular cortex was robust in healthy controls, reduced in epileptic rats between seizures, and nearly absent during seizures. This signal's reduction differed from that seen in satiated, unmotivated states, where waveform structure was preserved. The anterior insula appears to be a critical hub for gating auditory conscious awareness during seizures, offering a potential biomarker and intervention target.