Late Life Exercise Correlates with Improved Synaptic Function in Old People
Cognitive function depends on maintenance of the dynamic network of synaptic connections between neurons in the brain. In the study noted here, researchers assessed markers of synaptic density and function in postmortem human brains, and found a positive correlation with exercise regardless of the state of neurodegeneration. This is yet another good reason to maintain physical fitness into later life, keeping up with regular exercise. Supporting evidence suggests that a range of mechanisms link exercise with improved synaptic function, ranging from the fairly direct connection of reduced inflammation, and thereby improved performance in the cell populations that help to maintain synapses, to quite indirect connections involving the gut microbiome and generation of metabolites that change cell function in the brain.
The Memory and Aging Project (MAP), has been leading a longitudinal, prospective study since 1997 with volunteers who agree to undergo periodic cognitive and psychomotor assessments and to donate their organs for scientific purposes after death. The design of this study makes it possible to correlate daily habits and health states directly with structural and functional alterations in the brains of the participants.
The latest publication of that project presents results for 404 individuals whose physical activity was monitored with wristwatch or wristband-based devices for an average of 3.5 years ante-mortem. After death, samples were collected from up to twelve brain areas essential for cognitive and psychomotor skills; quantitative and functional analyses of eight synaptic proteins were performed on these samples, and a comprehensive histopathological evaluation, which examines ten neuropathologies associated with ageing, was made.
The results confirmed that higher rates of daily physical activity are associated across the board with an enrichment in the quantity and functionality of all the synaptic proteins analysed. This association was found to be most pronounced in brain regions related to motor control, such as the caudate nucleus and putamen. Furthermore, the relationship between physical exercise and synaptic density was independent of both the neuropathological load found in the same brain areas and the presence of pathologies affecting motor skills, indicating that physical activity can be beneficial for any elderly person regardless of their health status.
However, when analysed longitudinally, data indicated that the beneficial effects of physical exercise are highly volatile, as those participants with a high physical routine during early life and who discontinued this habit in the last two years of life had synaptic densities similar to those observed in more sedentary participants. In short, this study shows that physical exercise, even at an advanced age, contributes either towards promoting synaptogenesis processes or towards increasing synaptic resilience against the deleterious effects of neuropathological lesions."
Link: https://www.ehu.eus/en/web/campusa-magazine/-/physical-exercise-during-ageing-protects-brain-health
This sounds bad for exercise. Who drops exercise, after a lifetime of immense time and effort investment, in the last 2 years? Someone who's gotten sick and is in ill health. And then the observed brain benefits evaporate like dew in the sun.
As a Physio I recognise the truth of these findings.
As an 86 year old I find them hard to follow. A sedentary life is far more comfortable /pleasurable as you age. Exercise badly done or intermittently tends to cause exacerbations. The motivation to exercise regularly has slid away into an acceptance phase of life that I had not expected from me! It has had the expected consequences too.
But it is one so recognisable in the older patients I worked with.
A key piece of research in ageing must be how to refuel motivation.