Project Overview

The emerging consensus that the brain functions as a single, complex system has led to the popularity of a network approach to studying brain function. Functional connectivity, a measure of the coordinated activity between brain regions, has been observed in neuroimaging studies to change during aging and could be related to cognitive decline. However, in humans, neuronal activity cannot be measured directly. Instead, our main neuroimaging technique measures blood oxygenation which is an indicator of neuronal activity through the coupling between neurons and blood vessels. Given that aging is associated with changes in blood vessels and in neuron-vessel coupling, the neuronal and vascular contributions to functional connectivity during aging cannot be distinguished. Furthermore, the timeline of neurovascular changes during normal aging is not well known because it is typically measured only at one point in time.

One of our ongoing projects aims at establishing how microvascular structure evolves in mice brains using optical imaging measured during the course of aging. We also developed a framework for modeling neuroimaging signals from images of microvasculature. This new project will continue studying the microvascular origins of functional connectivity measured with neuroimaging, but with a more translational perspective. We will study the mice’s behavior and image their brains using noninvasive neuroimaging that could be applicable in humans. The results could yield knowledge on potential mechanisms underlying cognitive decline and better interpretation of clinical neuroimaging data.

Principal Investigator

Michèle Desjardins , Université Laval