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A V Bobrov

Publications and source records attributed to A V Bobrov.

8 recordsLinked to original sources

[Changes in the concentration of extracellular potassium and the slow negative potential in the somatosensory area of the cortex in response to stimulation of the ventroposterolateral nucleus of the thalamus in the cat].

A single electrical stimulus applied to the VPL nucleus with intensity, strong enough to elicit in gyrus sigmoideus posterior slow negativity following the primary response, caused a local increase in [K+]0 reaching 0.2 mM. On the basis of this finding it is supposed that the slow negativity reflects mainly depolarization.

Animals↗

[Changes in the extracellular potassium concentration and the slow negative potential in the cerebral cortex].

Changes of potassium concentration in the extracellular space ([K+]0) of the g. suprasylvius of cat cerebral cortex were recorded by means of K+ selective microelectrodes; the electrical field potential was recorded simultaneously. Under deep anesthesia a single electrical stimulus, applied to the cortical surface, at intensity enough to elicit the slow negativity, caused a local increase of [K+]0 reaching 0.1-1.5 mM. The time course of the K+ signal coincide with the course of the slow negativity. It is supposed that the slow negativity reflects glial depolarizaion arising under the action of K+ ions.

Animals↗

Spreading depression resulting from cortical punctures.

In acute experiments on cats under deep Nembutal anesthesia punctures of the cortex caused a prolonged negative shift of its surface potential (up to 15 mv, 5.5 min), which was followed by a prolonged positive shift. During these shifts of the potential, both components of the direct response were depressed. The changes in potential and the depression of electric activity spread over the cortex at a mean rate of 65 micrometers/s. The phenomenon arised when the punctures are made with a pipet 20 micrometers and above in diameter. A puncture of the surface structures was critical; passage of the pipet through the middle and deep layers was ineffective. It is assumed that when cortical punctures are made the SD is caused by K(+) ions which leak out of the destroyed glial structures.

Animals↗