Silva-Barrat C, Champagnat J
Institut Alfred Fessard, CNRS, Gif-sur-Yvette, France.
Neurosci Lett. 1995 Apr 14;189(2):105-8. doi: 10.1016/0304-3940(95)11464-8.
Bursting activities were investigated under conditions of reduced outward K+ currents in neocortical slices obtained from rats presenting the gamma-aminobutyric acid (GABA)-withdrawal syndrome (GWS), a focal epilepsy consecutive to the interruption of a chronic intracortical GABA infusion into the somatomotor cortex. These bursts were induced by intracellular depolarizing current injection and/or by white matter stimulation. Tetraethylammonium (TEA) at doses which did not change input resistance, spike duration or first interspike time interval abolished the burst terminating process and induced plateau-like potentials (up to 500 ms) which were tetrodotoxin-resistant and blocked by Ca2+ antagonists Cd2+ and Co2+. Therefore, it appears that bursts during GWS are generated by Ca(2+)-dependent plateau potentials which are terminated by a K+ current highly sensitive to TEA.
