Depolarization of brain cortex slices and synaptosomes by lithium. Determination of K+-equilibrium potential in cortex slices.
K+-equilibrium potential was determined in brain cortex slices of rat by measuring 86Rb+ distribution between the extra- and intracellular space. The ratio of internal to external Rb+ concentration was 39 +/- 1.8, corresponding to a resting membrane potential of 93.8 mV. Li+ (1-126 mM) decreased the membrane potential in both cortex slices and synaptosomes in a concentration-dependent manner. The presence of 1 mM Li+ was enough to cause a slight but distinct depolarization. During incubation in Li+-containing medium slices took up K+; however, for depolarization the presence of extracellular Li+ seemed to be necessary.
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D066298:In Vitro Techniques; D008094:Lithium / Q000378:metabolism / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D011188:Potassium / Q000378:metabolism*; D011868:Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D012413:Rubidium / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology
D011868:Radioisotopes; D008094:Lithium; D012413:Rubidium; D011188:Potassium