Effects of EGTA on the calcium-activated afterhyperpolarization in hippocampal CA3 pyramidal cells.
Intracellular recordings in the hippocampal slice preparation were made with electrodes filled with 0.2 molar potassium EGTA. The purpose was to investigate the role of calcium in mediating afterhyperpolarizations following bursts evoked by intracellular current pulses, arising spontaneously, or induced by the epileptogenic agent pencillin. In the first two cases the afterhyperpolarization was blocked and the associated conductance increase was reduced, suggesting that EGTA was blocking the calcium-activated potassium conductance during the hyperpolarization. In the third case the afterhyperpolarization and associated conductance increase persisted, implicating an alternative mechanism for the hyperpolarization. ?2Ns 04053
D000818:Animals; D002118:Calcium / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology*; D004553:Electric Conductivity; D004827:Epilepsy / Q000503:physiopathology; D005026:Ethylene Glycols / Q000494:pharmacology*; D006168:Guinea Pigs; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects*; D009433:Neural Inhibition; D011188:Potassium / Q000502:physiology; D011712:Pyramidal Tracts / Q000166:cytology / Q000502:physiology
D005026:Ethylene Glycols; D004533:Egtazic Acid; D011188:Potassium; D002118:Calcium