Aberrant neuronal connectivity in the cortex drives generation of seizures in rat Absence Epilepsy

Autor: Florian Studer, Guillaume Jarre, Benoit Pouyatos, Christian Nemoz, Elke Brauer-Krisch, Clémence Muzelle, Raphael Serduc, Christophe Heinrich, Antoine Depaulis
Přispěvatelé: [GIN] Grenoble Institut des Neurosciences (GIN), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA), European Synchroton Radiation Facility [Grenoble] (ESRF), Synchrotron Radiation for Biomedicine = Rayonnement SynchroTROn pour la Recherche BiomédicalE (STROBE), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut cellule souche et cerveau / Stem Cell and Brain Research Institute (U1208 Inserm - UCBL1 / SBRI - USC 1361 INRAE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), heinrich, christophe
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Brain-A Journal of Neurology
Brain-A Journal of Neurology, Oxford University Press (OUP), In press
Brain-A Journal of Neurology, 2022
ISSN: 0006-8950
1460-2156
Popis: Absence epilepsy belongs to genetic epilepsies and is characterized by recurrent generalized seizures that are concomitant with alterations of consciousness and associated with cognitive comorbidities. Little is known about the mechanisms leading to occurrence of epileptic seizures (i.e. epileptogenesis) and, in particular, it remains an open question as to whether neuronal hypersynchronization, a key feature in seizure initiation, could result from aberrant structural connectivity within neuronal networks endowing them with epileptic properties. In the present study, we addressed this question using a genetic model of absence epilepsy in the rat where seizures initiate in the whisker primary somatosensory cortex (wS1). We hypothesized that alterations in structural connectivity of neuronal networks within wS1 contribute to pathological neuronal synchronization responsible for seizures. First, we used rabies virus-mediated retrograde synaptic tracing and showed that cortical neurons located in both upper- and deep-layers of wS1 displayed aberrant and significantly increased connectivity in the genetic model of absence epilepsy, as highlighted by a higher number of presynaptic partners. Next, we showed at the functional level that disrupting these aberrant wS1 neuronal networks with synchrotron X-ray-mediated cortical microtransections drastically decreased both the synchronization and seizure power of wS1 neurons, as revealed by in vivo local field potential recordings with multichannel probes. Taken together, our data provide for the first time strong evidence that increased structural connectivity patterns of cortical neurons represent critical pathological substrates for increased neuronal synchronization and generation of absence seizures.
Databáze: OpenAIRE
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