Effect of Selank on Spontaneous Synaptic Activity of Rat Hippocampal CA1 Neurons.

Application of anxiolytic drug Selank to hippocampal slices increased the amplitude and discharge rate of spontaneous inhibitory postsynaptic currents in rat hippocampal pyramidal CA1 neurons. In some neurons, Selank-induced up-regulation of spontaneous inhibitory postsynaptic currents was preceded by a transient decrease in this activity. In the examined concentration range (1-8 µM), Selank demonstrated no significant dose-dependence.

Nootropic dipeptide noopept enhances inhibitory synaptic transmission in the hippocampus.

Application of nootropic agent Noopept on hippocampal slices from Wistar rats enhanced the inhibitory component of total current induced by stimulation of Shaffer collaterals in CA1 pyramidal neurons, but did not affect the excitatory component. A direct correlation between the increase in the amplitude of inhibitory current and agent concentration was found. The substance did not affect the release of inhibitory transmitters from terminals in the pyramidal neurons, which indicated changes in GABAergic interneurons.

[Peptidergic modulation of the hippocampus synaptic activity].

Effects of two newly synthesized nootropic and anxiolytic dipeptides: Noopept and Selank on inhibitory synaptic transmission in hippocampal CA1 pyramidal cells were investigated using patch-clamp technique in whole-cell configuration. Bath application of Noopept (1 microM) or Selank (2 microM) significantly increased the frequency of spike-dependent spontaneous m1PSCs, whereas spike-independent mlPSCs remained unchanged. It was suggested that both peptides mediated their effect sue to activation of inhibitory interneurons terminating on CA1 pyramidal cells. Results of current clamp recording of inhibitory interneurons residing in stratum radiatum confirmed this suggestion, at least for Noonent.