Dynamics of the development of microvascular reactions in the projection zones of the somatosensory cortex of the brain in rats.

The aim of the present work was to study the nature of local vascular reactions in the whisker projection zones of the somatosensory cortex of the rat brain in conditions of changes in sensory stimulation parameters. Studies were performed on Wistar rats anesthetized with ketamine. Local blood flow, neuron activity, and PO2 were recorded simultaneously in the cortical projection zones during mechanical stimulation of the whiskers. Local development of functional hyperemia was demonstrated in neuronal modules in conditions of threshold stimulation of the corresponding whisker. Increases in the intensity and frequency of stimulation of the whiskers were accompanied by decreases in the latent period and increases in the amplitude of regulatory microvascular reactions and a transformation in the configuration of functional hyperemia from a one-component pattern to a two-component pattern. The first component in the mechanism of development appeared to be associated with the action of factors of extravasal (including neuroglial) origin, while the second component appeared to be endothelium-dependent, as it did not occur in conditions of chemical deendothelialization.