EFFECT OF POTASSIUM ON HIPPOCAMPAL RIBONUCLEIC ACID CONCENTRATION

A cannula with normal (3.2 mEq) or higher than normal (7, 11, 25 mEq) K+ concentrations was placed on the hippocampus; this was considered artificially to cause corresponding modifications of (K+)0. Up to 11 mEq, K+ produced an increase of total hippocampal RNA concentration, and 25 mEq caused a decrease. The increase was attributed to an enhancement of spike-dependent transmitter release, as it was antagonized by 15 mEq Mg++ and by 30 mEq procaine. The possibility was considered that the increase of RNA was dependent on pyramidal cell firing, which would be enhanced by increased synaptic efficiency. Procaine, in the presence of normal K+, lowered the hippocampal RNA concentration. The decrease of hippocampal RNA found with 25 mEq K+ was related to the induction of seizures and to stimulation of the Na+-K+ pump. © 1969.