Oligodendrocytes in the aging brain.

Eleanor Catherine Sams

doi:10.1042/ns20210008

Abstract

More than half of the human brain volume is made up of white matter: regions where axons are coated in myelin, which primarily functions to increase the conduction speed of axon potentials. White matter volume significantly decreases with age, correlating with cognitive decline. Much research in the field of non-pathological brain aging mechanisms has taken a neuron-centric approach, with relatively little attention paid to other neural cells. This review discusses white matter changes, with focus on oligodendrocyte lineage cells and their ability to produce and maintain myelin to support normal brain homoeostasis. Improved understanding of intrinsic cellular changes, general senescence mechanisms, intercellular interactions and alterations in extracellular environment which occur with aging and impact oligodendrocyte cells is paramount. This may lead to strategies to support oligodendrocytes in aging, for example by supporting myelin synthesis, protecting against oxidative stress and promoting the rejuvenation of the intrinsic regenerative potential of progenitor cells. Ultimately, this will enable the protection of white matter integrity thus protecting cognitive function into the later years of life.

Highlights

Continuing progress in science and healthcare has led to an increased life-expectancy and an aging population in many parts of the world
A focus on the importance of white matter in aging was introduced and intensely researched by Bartzokis and colleagues [4–6]. This has led to a growing field of interest and understanding of brain aging as a network deterioration, such that the loss of myelination in white matter tracts which connect cortical regions underlies the loss of cognitive functions which rely on this network connectivity and efficient neuronal transmission
While the benefit of such nutrient support in the non-pathological aging brain remains hypothetical, there is strong evidence that nutritional interventions can be beneficial in the context of white matter repair following injury and demyelination, and in protecting cognitive function in pathologies associated with white matter, their utility in promoting healthy aging through oligodendrocyte support warrants further research

Summary

Introduction

Continuing progress in science and healthcare has led to an increased life-expectancy and an aging population in many parts of the world. We focus centrally on mature oligodendrocytes and OPCs within the aging brain environment and consider the impact of intrinsic and extrinsic age-related alterations on the ability of these cells to maintain myelination within CNS white matter.

Results

Conclusion