1. BLOOD MICROCIRCULATION IN MOUSE BRAIN WITH ALLOXAN DIABETES STUDIED BY TEMPORAL LASER SPECKLE CONTRAST IMAGING BLOOD MICROCIRCULATION IN MOUSE BRAIN WITH ALLOXAN DIABETES STUDIED BY TEMPORAL LASER SPECKLE CONTRAST IMAGING Polina Timoshina (1,2), Rui Shi (2), Yang Zhang(2), Dun Zhu(2), ValeryTuchin (1,2,3), Qingming Luo(2) 1- Research-Educational Institute of Optics and Biophotonics, Saratov State University, Russia 2- Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, China 3- Institute of Precision Mechanics and Control, Russian Academy of Sciences, Saratov, Russia

2. Introduction  The study of blood microcirculation is one of the most important problems of the medicine  This is caused by the fact that many diseases, such as cardio- vascular diseases, atherosclerosis, diabetes, chronic venous insufficiency cause functional and morphological changes of microcirculation of blood flow  We present the results of experimental study of changes of microcirculation of blood flow of brain in mice with diabetes by using Temporal Laser Speckle Contrast Imaging (TLSCI)  Additionally a direct effect of glucose water solution (concentration 20% and 40%) on blood microcirculation was studied

3. Methods and materials Animal model:  In our research we used white laboratory mice weighing 20-30 g  The animal model of aloxan induced diabetes was used  85 mg of alloxan was mixed with 2 ml of physiological saline  Experimental diabetes in laboratory animals was provided by a single subcutaneous injection of alloxan at a dose of 170 mg / kg body weight of the animal  In 10 days after injection of alloxan in experimental mice, analysis of glucose levels of blood using a glucometer was provided  The increase of blood glucose levels relative to a group of healthy mice was found

4. Methods and materials Optical method:  We used temporal laser speckle contrast analysis that is based on temporal statistics, computing of speckle contrast images using a sequence of speckle images acquired along a few time points instead of using a spatial window  To conduct the study Huazhong University of Science and Technology (HUST, Wuhan, China) team has developed a special software, which allowed us in real time to assess changes of diameter of blood vessels and relative velocity of blood flow

5. Experimental setup The measurements were carried out using a specially designed experimental setup: As a light source a He-Ne laser (632 nm) was used and a 12-bit CCD camera (pixel size ~ 6.45x6.45  m) combined with the microscope (Z16 APO, Leica, Germany working distance of 97 mm) was used to capture dynamic images with exposure time of 20 ms

6. Speckle images of internal organs: A) vessels of healthy brain after skull trepanation, B) vessels of diabetic brain after skull trepanation AB

7. Change of diameter of sagittal veins in brain: 1-control group 2- diabetic group

8. Change of relative values of velocity of blood of sagittal vein: 1-control group 2- diabetic group

9. Speckle images of vessels in the brain under the influence of optical clearing agent: A) without influence, B) after application of 20% solution of glucose C) after application of 40% solution of glucose a)b)c)

10. Change of relative values of diameter of sagittal vein

11. Results  It was shown that in brain of diabetic group diameter of sagittal vein is increased and the speed of blood flow decreased relative to the control group  Topical application of 20%- and 40%- glucose increases diameter of blood vessels  Study of blood microcirculation disorders of brain at diabetes show that disease development in animals causes changes in the microcirculatory system

12. Acknowledgements Saratov State University Department of Optics and Biophotonics Saratov Fall Meeting 2014 We thank Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology (Wuhan, China) for support of these researches This work was partially supported by RF Presidential grant 703.2014.2 “Scientific School Support” and Grant #13-02-91176 of Russian Foundation of Basis Research