Role of inhibitory control in modulating spread of focal ictal activity [article]

Jyun-you Liou, Hongtao Ma, Michael Wenzel, Mingrui Zhao, Eliza Baird-Daniel, Elliot Smith, Andrew Daniel, Ronald G. Emerson, Rafael Yuste, Theodore H. Schwartz, Catherine Schevon
2017 bioRxiv   pre-print
Focal seizure propagation is classically thought to be spatially contiguous. However, propagation through the epileptic network, a collection of disparate epileptic nodes, 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 propagation beyond a 2-3 mm region, they were associated with
more » ... ide LFP fluctuations and parvalbumin-positive interneuron activity outside the seizure focus. Globally compromising this inhibitory response using bicuculline surface application resulted in classical contiguous propagation; whereas, focal bicuculline microinjection resulted in epileptic network formation with two physically disparate foci. Our study suggests both classical and epileptic network propagation could arise from inhibition defects without pre-existing pathological connectivity changes, and that preferred propagation pathways may result from variations in cortical topology.
doi:10.1101/146407 fatcat:ul3mhwxwergexgjix225cj3rxa