Effect of endogenous peptides on the currents Of NMDA- AND AMPA-receptors of neurons of the cortex, hippocampus and cerebellum of rat brain

Abstract

The obtained results show that endogenous peptides play an important role in the regulation of the glutamatergic mediator system of the brain. They act in extremely low concentrations, starting at 1 × 10–14 M, their effects are concentration-dependent and reversible, thus indicating the exclusive specificity of the corresponding receptors. The range of their influence on responses of postsynaptic glutamate receptors is rather narrow and, as a rule, does not exceed 60-70% of control. We have demonstrated for the first time that CLIP blocks NMDA receptors and potentiates AMPA receptors in a wide range of concentrations (6 orders of magnitude); this is very important for manifestation of memory-stimulating effect. Somatostatin blocking NMDA receptors and potentiating AMPA receptors, also plays an important role in the mechanisms of memory formation. Obviously, there is a great similarity in the action of both peptides on AMPA and NMDA receptors. Thus our results provide the first information about regulation of including cognitive processes and memory mechanisms by endogenous compounds. This mechanism particularly involves regulation of AMPA and NMDA receptors in the brain.