Effects of barium on stimulus induced changes in extracellular potassium concentration in area CA1 of hippocampal slices from normal and pilocarpine-treated epileptic rats.
Laminar profiles of rises in [K+]o and slow field potentials induced by alvear stimulation were recorded in area CA1 of hippocampal slices from control and pilocarpine-treated rats in absence and presence of Ba2+. In control animals, Ba2+ augmented rises in [K+]o in stratum pyramidale (SP) as well as in stratum radiatum (SR). In pilocarpine-treated animals an augmentation of rises in [K+]o was restricted to SP and its immediate vicinity. Moreover, the effect of Ba2+ in SP was small or missing in eight out of 15 slices of pilocarpine-treated animals. In these slices laminar profiles of rises in [K+]o were not affected by Ba2+. It is suggested that spatial K+-buffering is reduced in area CA1 of epileptic animals.
Gabriel
S
S
Abt. Neurophysiologie, Institut für Physiologie, Universitätsklinikum Charité/Virchow-Klinikum, Humboldt-Universität zu Berlin, Germany.
Eilers
A
A
Kivi
A
A
Kovacs
R
R
Schulze
K
K
Lehmann
T N
TN
Heinemann
U
U
D000818:Animals; D001464:Barium / Q000494:pharmacology*; D004833:Epilepsy, Temporal Lobe / Q000139:chemically induced / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010477:Perfusion; D010862:Pilocarpine / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012601:Scopolamine / Q000494:pharmacology
D010862:Pilocarpine; D001464:Barium; D012601:Scopolamine; D011188:Potassium