Abstract: Objective To investigate the feasibility and efficacy of improved closed spinal window applied to assess the rat dorsal pial microcirculation by fluorescence microscopy. Methods On the 8-week-old SD rats, we made a precise improved closed spinal window with a laminectomy at the T10 level using a dental acrylic resin and a cover glass. The window was placed over the back of the rat with intact dura. Pasted the dental acrylic resin onto the spinous processes at the T9 and T11 as fixed aids. Collect 100μL hematocrit red blood cells (BRC) by centrifugation (2000×g). The RBC labelled by Dil (5 mg/L) in vitro were injected in jugular vein. Leukocytes labelled with rhodamine 6G were injected intravenously (0.3 g/L). The spine was fixed with vertebral fixation device. Local microcirculation is recorded in real time through the window. Results Microvascular morphology, distribution and blood vessel density can be observed. Dil-labeled RBC velocity and adhesion were observed. Leukocyte adherence to pial vessels and assessment of perfusion were observed with the help of rhodamine 6G. Conclusion By improved closed spinal window and vertebral fixation device, we observed the microcirculation in the rat pia.

Key words: rat, spinal, microcirculation, intravital fluorescence, spinal window