Effects of voluntary exercise on structure and function of cortical microvasculature
Tóm tắt
Aerobic activity has been shown highly beneficial to brain health, yet much uncertainty still surrounds the effects of exercise on the functioning of cerebral microvasculature. This study used two-photon fluorescence microscopy to examine cerebral hemodynamic alterations as well as accompanying geometric changes in the cortical microvascular network following five weeks of voluntary exercise in transgenic mice endogenously expressing tdTomato in vascular endothelial cells to allow visualization of microvessels irrespective of their perfusion levels. We found a diminished microvascular response to a hypercapnic challenge (10% FiCO2) in running mice when compared to that in nonrunning controls despite commensurate increases in transcutaneous CO2 tension. The flow increase to hypercapnia in runners was 70% lower than that in nonrunners (p = 0.0070) and the runners’ arteriolar red blood cell speed changed by only half the amount seen in nonrunners (p = 0.0085). No changes were seen in resting hemodynamics or in the systemic physiological parameters measured. Although a few unperfused new vessels were observed on visual inspection, running did not produce significant morphological differences in the microvascular morphometric parameters, quantified following semiautomated tracking of the microvascular networks. We propose that voluntary running led to increased cortical microvascular efficiency and desensitization to CO2 elevation.
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Tài liệu tham khảo
Chalimoniuk M, 2015, J Physiol Pharmacol, 4, 539
Yoshihara K, 2009, Physiol Meas, 20, 293
Deming WE, 1943, Statistical adjustment of data. 1985th Dover Publications edition
Cipolla M, 2009, The cerebral circulation, 29
Ludyga S, Gronwald T and Hottenrott K. The athlete’s brain: cross-sectional evidence for neural efficiency during cycling exercise. Neural Plast 2016; Article ID 4583674.
De Kimpe SJ, 1994, J Pharmacol Exp Ther, 268, 910