[Is the electrical activity of the brain always electrical? (The factors that generate the potential of a metal electrode in direct contact with the brain)].

In the paper are analysed the factors creating slow potential changes of a metal electrode directly contacting with the living tissue. In the paper are presented the data according to which electrochemical tissue activity participates in creating the electrode potential besides the electrical activity. The paper carries a discussion character.

[An analysis of the dipole characteristics of the evoked potentials of the cerebral cortex].

Possibility is studied of application of the current dipole in uniform unlimited medium for description of the sources of the evoked potentials recorded epidurally and on the skull surface. By means of computing experiment the influence is analyzed of per-layer heterogeneity of skull and scalp conductivity on precision of the solution of the inverse problem of electroencephalography with the use of the above model. It is shown that at epidural focal recording of the potential, the application of the model is adequate, and at extracranial recording introduction of additional corrections is required.

[Multineuronal cortical activity in dogs with a defensive instrumental conditioned reflex].

By methods of correlation analysis, interrelations were studied of neurones with high, mean and low amplitudes of spikes singled out by amplitude principle from background multineuronal activity of the motor and somatosensory cortical zones, recorded by chronically implanted semi-microelectrodes in dogs. In trained animals, a high positive correlation was observed of singled out neurones discharges, particularly between the neurones with low and mean amplitude of spikes. By the method of cross-interval histogram, dependent relations were revealed of the neurones with different amplitude characteristic mainly of one-sided excitatory character.

[Effect of preliminary presentation of a future conditioned stimulus on the rate of elaboration of an instrumental defensive reflex in the rat].

Preliminary presentation of future conditioned stimulus without reinforcement delayed and then accelerated subsequent elaboration of defensive conditioned reflex to this stimulus in rats. Preliminary presentation of resembling stimuli influenced the speed of conditioning in a lesser degree. It is suggested that such changes are due to formation of a local conditioned reflex to the future conditioned stimulus.