Year: 2017
Type: preprint
Abstract: Focal seizure propagation is classically thought to be spatially contiguous. However, distribution of seizures through a large-scale epileptic network has been theorized. Here, we used a multielectrode array, wide field calcium imaging, and two-photon calcium imaging to study focal seizure propagation pathways in an acute rodent neocortical 4-aminopyridine model. Although ictal neuronal bursts did not propagate beyond a 2-3 mm region, they were associated with hemisphere-wide field potential fluctuations and parvalbumin-positive interneuron activity outside the seizure focus. While bicuculline surface application enhanced contiguous seizure propagation, focal bicuculline microinjection at sites distant to the 4-aminopyridine focus resulted in epileptic network formation with maximal activity at the two foci. Our study suggests that both classical and epileptic network propagation can arise from localized inhibition defects, and that the network appearance can arise in the context of normal brain structure without requirement for pathological connectivity changes between sites.
DOI: 10.1101/146407
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funders: National Science Foundation, Simons Foundation, National Institutes of Health, Multidisciplinary University Research Initiative, National Institute of Mental Health, National Eye Institute, National Institute of Neurological Disorders and Stroke, Army Research Office, Army Research Laboratory
Awards: G1242600127, Dynamics of long range network interactions in focal epilepsy, G1376878605, G2321596477, G2723399458, G2809749118, G4012432327, Functional consequences of GABAergic inhibition of dendritic spines at puberty, G5259331294, Imaging Functional Connectivity in Visual Cortex, Functional connectomics of the neocortical microcircuit, Collaborative Research in Biophotonics: Implantable sensor for brain blood flow mapping, G7255690952, G7452299184, Two-photon optical control of astrocytic function
OpenAlex ID: W2621537359