[Action of beta-carboline derivatives on the evoked activity of hippocampal neurons].

The effects of tetrahydro-beta-carboline-3-carbonic acid methyl ester (I), 1-phenyl-tetrahydro-beta-carboline-3-carbonic acid methyl ester (II), tetrahydro-beta-carboline-3-carbonic acid methylamide, and beta-carboline-3-carbonic acid methylamide on evoked potentials (EP) of neurons were investigated in experiments with hippocampal slices. Each compound was tested in 5 experiments. These derivatives applied in a concentration 4 M had the following features in common: 1) a 10-20% augmentation of the amplitude of the population spike (PS) evoked in the CAI area by Schaffer collaterals stimulation; 2) appearance of additional PSs; 3) potentiation of the substance effect after beginning of washing; 4) poor washing (incomplete recovery of EP after 40-60 min of washing). In one of five experiments, I administration led to a decrease in the PS amplitude (by 15%). A similar effect was observed in one of five experiments during perfusion of II. The authors assume that there are hippocampal mechanisms responsible for realization of opposite effects associated with occupation of benzodiazepine receptors by ligands.