Labo Neurosciences

Bienfaits de l'activité physique sur les fonctions du cerveau

L’évaluation des effets de l’entraînement physique sur le fonctionnement perceptif et cognitif est une autre façon de vérifier l’incidence de l’environnement et de l’expérience sur le développement du cerveau humain. Les objectifs de cet axe de recherche sont :
1) d’identifier les paramètres de l’activité physique qui se traduisent en une facilitation de certains processus perceptifs et cognitifs chez l’enfant, immédiatement après que l’activité est réalisée; 2) de mesurer la durée des effets facilitateurs; et 3) d’évaluer l’effet de programmes d’entraînement physique sur les fonctions du cerveau. Ultimement, les résultats de ces études permettront de faire le transfert entre la recherche fondamentale et l’application clinique en procurant les lignes directrices qui guideront l’élaboration de programmes d’entraînement physique qui viseront l’optimisation des fonctions du cerveau de l’enfant.

Projets récents :

The effects of acute physical exercise on cognitive function during development

Although accumulating research suggests that an acute bout of physical exercise ameliorates cognitive function in adults, very little is known about the effects of acute exercise on cognitive functioning during development. We assessed simple and choice reaction times in groups of 7- and 10-year-old boys (n = 36 children per age group). Immediately prior to testing, half of the children in each age group completed an aerobic activity for a duration of 30 minutes, whilst the other half watched a television show of the same duration. Compared to a group of boys who were physically inactive, the boys who completed the aerobic activity were significantly faster on the simple and the choice reaction time tasks. Further, for both age groups outcome was even better for the choice reaction time task compared to the simple reaction time task, indicating that exercise ameliorates cognitive processes as well as sensori-motor processes. These findings indicate that physical exercise in children does not only benefit physical health but that it also benefits cognitive health.


Effect of exercise during human pregnancy on the new born’s brain

Accumulating evidence suggests that an active lifestyle is beneficial for cognition in children, adults and the elderly. Recently, studies using the rat animal model found that maternal exercise during pregnancy has a beneficial influence on the development of the foetal brain (i.e., increased hippocampal neurogenesis) that ultimately leads to functional changes for the newborn rat pups (i.e., better memory and learning abilities). The aim of the present study was to verify if in humans an active lifestyle during pregnancy has an impact on the newborn's brain. Twenty-two women are enrolled in the study and were randomly assigned to an active or a sedentary group. The active group was asked to exercise a minimum of 20 minutes, 3 times per week, at a minimal intensity of 55% of their maximal aerobic capacity. The sedentary group did not exercise. Monitoring was done using a daily exercise log with pedometer readings and the periodic wearing of an accelerometer. Other measures taken include a nutrition journal, and pre-pregnancy exercise habits. The effect of exercise during pregnancy on the newborn's brain was investigated 8 - 12 days post partum by means of the mismatch negativity (MMN), a neurophysiological brain potential that is associated to auditory sensory memory and measured with electroencephalography. Mann-Whitney test was used to investigate statistical significance of results. No significant difference was found between the two groups for mean amplitude (P > 0.5). On the other hand, mean median latency at the left and right fontal locations (F3 & F4) was significantly slower for the babies of the active mothers (258ms.) than the babies of the sedentary mothers (180 ms.) (z=-2.324, p=0.20). These findings suggest that exercise during pregnancy has an impact on the development of the newborn’s brain.



A meta-analysis on Exercise and Primary Open Angle Glaucoma

Elevated intraocular pressure (IOP) is one of many risk factors involved in the progression of Primary Open Angle Glaucoma (POAG) and clinically it remains the most easily controllable. However, POAG progresses asymptomatically over years and only 60 to 70% of patients comply with long term drug regimes. For over four decades researchers have examined the relationship between aerobic exercise and reduction of IOP. Exercise could be an important complementary chronic treatment; yet, for an exercise program to be considered a viable early intervention for those at risk it is important to identify the most effective combination of intensity and duration. To begin that investigation a meta-analysis was performed to compare the effect of these exercise parameters on IOP levels in a non-clinical population. Searches were conducted via PubMed and Google scholar and 63 studies were obtained. Studies were excluded as per the requirements of the analysis or a lack of variance measures related to the mean change in IOP. The ten studies selected include sedentary or normally-active participants with normal baseline IOP (10 to 21 mmHg) who completed a single bout of mild (40% HR) to moderate (50 to 70% HR) aerobic exercise ranging from 2 to 60 minutes. There is a clear effect of exercise with a 1 to 5 mmHg reduction in IOP across conditions. Although we could not compute a global effect size because the 21 conditions did not each come from independent groups, we observe certain patterns in the results. First, the active and sedentary participants appear to benefit equally from exercise. Second, there is an almost twofold reduction in IOP from the mild to moderate intensity conditions. Finally, the duration of exercise does not appear to influence outcome for moderate intensity exercise while it does for the mild conditions. The reduction in IOP as a result of exercise is within the range that is most useful to those at risk of POAG. Prescription of even a mild daily aerobic exercise regime could be an effective method to keep slightly elevated IOP levels within a normal range. The relationship between intensity and duration needs to be analyzed further in a longitudinal study that focuses on individuals at risk for POAG.