test
Search publications, data, projects and authors

Thesis

French

ID: <

10670/1.rri6fp

>

Where these data come from
Olfactory enrichment during aging : improvement of Noradrenaline and model of cognitive reserve

Abstract

Aging is an inevitable and complex biological phenomenon associated with a progressive decline of sensory, motor and cognitive functions with time, affecting life quality and health. Normal brain aging is accompanied by functional and structural changes, leading to cognitive decline. Among these changes, age-related alterations of the noradrenergic system seem to contribute significantly to cognitive deficits. Conversely, the integrity of the Locus Coeruleus seems to allow healthy cognitive aging. A potentially powerful tool to achieve successful brain aging is to boost the cognitive reserve, associated with higher level of brain stimulation and modulations in brain activation and connectivity in humans. In rodents, environmental enrichment, increasing sensory stimulations, motor activity and social interactions, mimics the conditions leading to constitution of the cognitive reserve in humans and has largely proven cognitive benefits.The goals of this thesis are, in the first place, to study the role of Noradrenaline in the maintenance of structural plasticity and olfactory discrimination abilities in aged mice, then secondly, to test the olfactory enrichment as a model of the cognitive reserve build-up.In the first study, we used the olfactory perceptual learning paradigm to investigate the contribution of Noradrenaline to the maintenance of structural plasticity and cognitive abilities during aging in mice. This learning consists in an improvement of the discrimination between perceptually close odorants after repeated exposure to these odorants. Our results suggest that the local release of Noradrenaline in the olfactory bulb, by optogenetic stimulation of Locus Coeruleus fibers allows the maintenance of discrimination abilities during aging. Our data also reveal a form of structural plasticity of the noradrenergic innervation in the aged olfactory bulb. The overall work supports a contribution of Noradrenaline to healthy brain aging.In a second study, we used a strategy based on repeated olfactory enrichment during the whole life of the animal in order to enable the cognitive reserve buildup. Such enrichment maintained olfactory discrimination performances at late ages. Interestingly, mice’s performances in spatial memory and cognitive flexibility improved too. This result indicates that the benefits of an odor-based enrichment extend beyond the olfactory sphere and include broader cognitive benefits on age-sensitive functions. We thus propose lifelong olfactory enrichment as model of the cognitive reserve build-up to further identify its cellular basis and test the contribution of Noradrenaline to cognitive reserve build-up and healthy brain aging

Your Feedback

Please give us your feedback and help us make GoTriple better.
Fill in our satisfaction questionnaire and tell us what you like about GoTriple!