Absence-like Seizures, Cortical Oscillations Abnormalities and Decreased Anxiety-like Behavior in Wistar Audiogenic Rats with Cortical Microgyria

Author(s)

Zanona, Querusche Klippel ; Marconi, Gabriel Alves ; Couto Pereira, Natividade de Sa ; Lazzarotto, Gabriela ; Ferreira Donatti, Ana Luiza ; Cortes de Oliveira, Jose Antonio ; Garcia-Cairasco, Norberto ; Calcagnotto, Maria Elisa

• Document type: Journal article
• Source: Neuroscience; v. 500, p. 15-pg., 2022-08-17.

Abstract

Wistar Audiogenic Rats (WAR) is an inbred rodent strain susceptible to acute auditory stimulation-induced seizures. However, spontaneous epileptic seizures (SES) and their associated electroencephalogram (EEG) abnormalities have not been reported in WAR kindled animals. The same is true for naive WARs (without sound-induced seizures). An approach to increment epileptogenesis and SES is to use a second insult to be added to the genetic background. Here, we used adult naive WARs with microgyria induced by neonatal cortical freeze-lesion (FL) to evaluate the occurrence of SES and the modification in cortical oscillation patterns and behavior. The neonatal cortical FL was performed in Wistar and naive WARs (Wis-FL and WAR-FL). Sham animals were used as controls (Wistar-S and WAR-S). Video-EEG recordings and behavioral tasks were performed during adulthood. Surprisingly, spike-waive discharges (SWD) events associated with behavior arrest were detected in WAR-S rats. Those events increased in duration and number in WAR-FL animals. The EEG quantitative analysis showed decreased power of cortical delta, theta and beta oscillations in WAR-S, decreased power of cortical fast gamma (FG) oscillations in WARs, independent of microgyria, and decreased interhemispheric synchrony for delta and FG with stronger coupling in delta and theta-FG oscillations in FL animals. The WARs, regardless of microgyria, had reduced locomotor activity, but only WAR-FL animals had reduced anxiety-like behavior. Microgyria in naive WARs intensified SWD events associated with behavior arrest that could reflect absence-like seizures and abnormal cortical oscillations, and reduced anxiety-like behavior indicating that WAR-FL could be a reliable model to study epileptogenesis. (C) 2022 IBRO. Published by Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 19/05957-8 - Epilepsies and neuropsyquiatric comorbidities: characterization of the effects of the treatment with cannabidiol and HUF-101 in in vivo and in vitro experimental models
• Grantee: Norberto Garcia Cairasco
• Support Opportunities: Regular Research Grants