[Alteration of the slow cortical potential and neuronal activity during elaboration of conditioned reflexes in rabbits]. / Izmenenie medlennogo potentsiala kory i neironal'noi aktivnosti pri vyrabotke uslovnykh refleksov u krolikov.

In experiments on alert rabbits it was shown that during the first blinking conditioned reflex to a sound, a slow negative potential appears in response to the conditioned signal in the auditory area of the cortex. At the cellular level, this correlates with the formation of polysensory neurone activity accompanied by a small increase in its action potential duration (generalization of excitation, depolarization). During stabilization of the reflex, its specialization, coordinative inhibition of other central responses related to narrowing of receptive areas, --a slow positive potential is evoked in EEG by the conditioned stimulus. At the cellular level correspondingly, a shift is observed from group discharges during intersignal periods to single rhythmic discharges in response to conditioned stimulation (concentration of excitation, lowering of excitability).

[Stationary exitation according to A.A. Ukhtomskii and its role in the mechanism of completion of temporary connections]. / Statsionarnoe vozbuzhdenie po A.A. Ukhtomskomu, i ego rol' v mekhanizme zamykaniia vremennoi sviazi

When recording potentials form the cortical surface, an increase in the processes of local excitation was shown to occur at the moment of revealing the first signs of the conditioned reflex: appearing of slow waves, increasing amplitude of evoked potentials, negative shift of the cortical steady potential. When recording evoked potentials from deep cortical layers, successive stages of transition of the local excitation into a spread one which carries out the conditioning, were shown. Stationary depolarization occurring in conditioning and revealed in gross forms as slow waves, increasing amplitude of evoked potentials, and negative shift of steady potential, at the cellular level is revealed as formation of neuron's polysensory acitvity and is usually followed by increase in the action potential (AP) duration in neurons of the cortical ends of analysers participating in conditioning. Etimizol is known to improve memory processes in man and in animals (2). When acting on the mollusk neurons, etimizol increases AP duration by 144 plus or minus 64 percent. The data obtained suggest that the observed in conditioning increase of AP durration of neurons in the cortical representation of conditioned and unconditioned stimuli is associated with alterations in ion exchange and with trace processes in neurons, which apparently is related to the fine mechanisms underlying the retention in memory.

[Elektrophysiological parameters of mollusk neurons under the influence of etimizol]. / Elektrofiziologicheskie parametry neironov molliuska pri deistvii étimizola

Extracellular application of 5--10 mM/L etimizol exerted a specific effect on the giant neurons of the Coretus corneus isolated nervous system: action potential duration increased significantly, speed of development of its descending phase decreased, as well as the trace hyperpolarization amplitude. The effect was reversible and depended upon the etimizol concentration and the initial functional state of neurons. Etimizol is supposed to decrease the K-+ permeability of neurons' membrane during action potential. Large concentrations of etimizol decrease, probably, the Na+ permeability as well as suggested by reducing maximum of the ascending phase of action potential.