Dimethylethanolamine decreases epileptiform activity in acute human hippocampal slices in vitro

Human hippocampal tissue from epilepsy surgery was collected from 12 TLE patients (ten male, two female) and cut in the laboratory to 400 µm slices. Field potential recordings were performed with borosilicate pipettes pulled with a vertical puller (1-2 MΩ) and filled with NaCl (154 mM). Signals were recorded from CA1 pyramidal cell layer, sampled at 10 kHz, low-pass filtered at 2 kHz by a Digidata 1550 interface and processed by PClamp10 software (Molecular Devices, Sunnyvale, CA, USA).<br> Epileptiform activity was induced by 8 mM KCl and 4-aminopyridin (4-AP, 100 µM, Sigma). For details on drug application sequence see README. Recordings were band pass filtered (1-1000 Hz) and the last 5 min of each application phase were analyzed with Clampfit 10.7 (Molecular Devices, Sunnyvale, CA, USA) threshold analysis. All events visually identified as burst activity (defined by positive and negative deflection and a duration ≥100 ms) were manually indicated for further analysis of event frequency (inter-event-interval, IEI), amplitude and total number of events during the analyzed time frame.