Effects of aerobic exercise training on cognitive function and cortical vascularity in monkeys

Abstract

This study examined whether regular exercise training, at a level that would be recommended for middle-aged people interested in improving fitness could lead to improved cognitive performance and increased blood flow to the brain in another primate species. Adult female cynomolgus monkeys were trained to run on treadmills for one hour a day, 5 days a week, for a 5 month period (n=16; 1.9±0.4 miles/day). A sedentary control group sat daily on immobile treadmills (n=8). Half of the runners had an additional sedentary period for 3 months at the end of the exercise period (n=8). In all groups, half of the monkeys were middle-aged (10-12 years old) and half were more mature (15-17 years old). Starting the fifth week of exercise training, monkeys underwent cognitive testing using the Wisconsin General Testing Apparatus (WGTA). Regardless of age, the exercising group learned to use the WGTA significantly faster (4.6±3.4 days) compared to controls (8.3±4.8 days; p=0.05). At the end of 5 months of running monkeys showed increased fitness, and the vascular volume fraction in the motor cortex in mature adult running monkeys was increased significantly compared to controls (p=0.029). However, increased vascular volume did not remain apparent after a three-month sedentary period. These findings indicate that the level of exercise associated with improved fitness in middle-aged humans is sufficient to increase both the rate of learning and blood flow to the cerebral cortex, at least during the period of regular exercise.

Exercise and Environmental Enrichment as Enablers of Task-Specific Neuroplasticity and Stroke Recovery

“…Improvement in cognitive function is correlated with changes in plasticity-related genes and growth factors [33], neurogenesis [36], and endothelial cell proliferation [37]. Aerobic exercise has also been shown to induce cortical angiogenesis and improve executive function in middle-aged Cynomolgus monkeys [38].…”

Linking brains and brawn: exercise and the evolution of human neurobiology

“…Activity-induced neurogenesis has a major impact on cognitive function and on the size of brain components. For example, performance in memory and spatial learning tasks improves following APA in non-human taxa such as monkeys [30] and rodents [8,31,32]. In humans, aerobic fitness is positively correlated with hippocampal and basal ganglia volume in children and older adults [25,33,34], with grey matter density in the insula of young adults [35], as well as with the amount of grey and white matter in the frontal lobe and other brain areas of older adults [27].…”

Cerebral blood flow and cerebrovascular reactivity at rest and during sub-maximal exercise: Effect of age and 12-week exercise training

“…One cross-sectional study indicated that higher fitness is related to larger frontal and temporal volumes of grey matter (Colcombe et al 2006). Other potential mechanisms may involve more endotheliumdependent vasodilatation as a result of more NO bioavailability (Green et al 2004) and/or cerebral angiogenesis (Rhyu et al 2010;Swain et al 2003;Ding et al 2006;Black et al 1990). In support of this, ageinduced cerebral atrophy appears to be less marked in those with higher aerobic fitness (Colcombe et al 2003).…”