Characterization of a hippocampal model of epileptiform activity

Epileptiform activity (EA) comprises abnormal excessive neuronal discharges (spikes and sharp waves) detectable by electroencephalogram. The term EA originates from epilepsy research, where interictal EA appears in EEG between seizures. Importantly, EA occurs not only in epilepsy but also in various pathologies, possibly contributing to cognitive impairment. EA has been observed in neurodegenerative disorders like Alzheimer's and Parkinson's diseases. However, a direct causal link between EA and cognitive impairment remains elusive. A significant issue is the lack of a pure EA model for investigating this link unequivocally. Here, we assess whether intrahippocampal injection of low-dose KA to mimic EA—without inducing seizures—affects emotional, cognitive, and electrophysiological aspects in 2-month-old male and female mice. We have now developed a pure EA model, with preliminary data indicating neuronal alterations at the cellular level, changes in electrophysiological recordings, and deficits in cognitive behavioral tests. Currently, we are conducting electrophysiological and immunohistological characterization. Our findings suggest that interictal EA alone can impair learning and memory in mice.