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PresentationsMethod of analysis of local flow velocity variability in the microcirculatory network of the brain: search for the activity of regulatory mechanismsNational Research Saratov State University named after N.G. Chernyshevsky, Russia, 410012, Saratov, Astrakhanskaya st., 83, dethaos@bk.ru 1Kursk State University, Russia, 305000, Kursk, University Street, Russia, 305000, Kursk, Radishcheva Street, 33, E-mail: postnicov@gmail.com The desire for a more detailed analysis of the structures and processes of the brain entails increased requirements for the spatial-temporal resolution of analysis methods. One of the most effective approaches to achieving the required accuracy and relative ease of implementation of invivo experiment is the combination of traditional and new techniques. In the task of analyzing flows in microvessels, one of the main characteristics is the velocity. Analysis of velocity fluctuations caused by the cardiac cycle, vasomotions, or other rhythmic processes can play a significant role in both monitoring normal and identifying pathological conditions [1]. The fact that the velocity is inhomogeneous across the vessel space of the vessels and it fluctuates on a time scale increases interest in this parameter as a characteristic of local changes in blood flow. [2]. In the problem of studying the velocity at the scale of an individual vessel, an approach based on the analysis of the wavelet coherence of the contrast of the dynamic speckle field induced by a coherent light source is proposed. An alternative algorithm for processing speckle data based on the use of a sliding Gaussian filter has been developed. It has been shown that this approach has an advantage in the detection of small blood vessels. The developed algorithm is applied to the results of invasive experiments on microvessels of the mouse brain in order to map the flow velocity and spatial heterogeneity of its fluctuations. In the analysis of the flows of two different vessels in the same field of view by the wavelet coherence method, a phase shift at the heart rate frequency and a synchronous character at the respiration rate were recorded. So, the proposed method of detection, visualization and analysis, with its further development, can be applied in studies of the variability of blood flow in the brain network and in revealing the activity of local and central regulatory mechanisms.
References. 1. Wagshul M. E., Eide P. K. The pulsating brain: a review of experimental and clinical studies of intracranial pulsatility // Fluids Barriers CNS, Т. 8, № 1, 2011, С. 1-23 2. Kolar M. et al. Changes of cortical perfusion in the early phase of subarachnoid bleeding in a rat model and the role of intracranial hypertension // Physiol Res., Т. 66. – №. Suppl 4. 2017, С. S545-S551.
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