Learn about the flu shot, COVID-19 vaccine, and our masking policy »
New to MyHealth?
Manage Your Care From Anywhere.
Access your health information from any device with MyHealth. You can message your clinic, view lab results, schedule an appointment, and pay your bill.
ALREADY HAVE AN ACCESS CODE?
DON'T HAVE AN ACCESS CODE?
NEED MORE DETAILS?
MyHealth for Mobile
Get the iPhone MyHealth app »
Get the Android MyHealth app »
Abstract
It has been proposed that the notable capacity for epileptogenesis in the hippocampus may be related to potassium accumulation in extracellular spaces. To investigate this hypothesis more directly, we measured changes in extracellular potassium concentration ([K+]o) during focal hippocampal epilepsy using potassium-sensitive microelectrodes. Interictal and ictal electroencephalographic events were accompanied by increases in [K+]o that varied systematically with depth from the ependymal surface and lateral distance from the focus. Maximal [K+]o changes during interictal and ictal discharges occurred in the stratum pyramidale. Initiation of ictal activity did not correlate with a particular "threshold" [K+]o. Comparing these results with similar data from neocortex, we observed that interictal K+ responses in hippocampus lasted longer and had slower rise times, and that peak interictal and ictal [K+]o values were consistently lower. Increases in [K+]o cannot be the sole explanation for regional variations in seizure susceptibility, interictal-ictal transitions, or termination of ictal episodes.
View details for Web of Science ID A1976BD60300002
View details for PubMedID 1252153