[Blood flow in the microvessels of the cerebral cortex].

To measure dynamic characteristics of linear velocity of the blood flow in microvessels on the surface of rat's brain, the method of accelerated cinemicrography was used. The blood flow velocity varied from 500 to 5000 mu/sec in microvessels with diameter of 7-15 mu. The blood flow fluctuated with the rate of 1-3 oscillations per second and the amplitude 20-50% of the average value. Auto- and crosscorrelation analysis of the processes revealed in 35% of the cases a positive correlation between shifts of velocities and the frequency of their occurrence. No correlation existed between rapid changes of the blood flow in adjacent or distant microvessels. The sharp changes of blood flow seem to be due to periodical passage of leucocytes and accumulated erythrocytes which increase resistance against the blood flow in microvessels.