Heterogeneity of Astrocyte Reactivity

Astrocytes, the bushy, star-shaped glial cells of the brain and spinal cord, support the proper development and function of many cells in the central nervous system. In response to disease or injury they transform, adopting varied morphologies, molecular signatures, and functions—this state of transformation is known as reactivity. For over a century, the reactivity of astrocytes has been recognized, but it is the recent surge in technological innovation that has shed light on the diverse nature of this reactivity. It is this developing understanding of the heterogeneity of reactive astrocytes across disease-specific contexts and a spatiotemporal gradient that now excites the astrocyte field. In this review, we discuss the current understanding of reactive astrocyte heterogeneity, highlight the biological implications of this heterogeneity, and propose future approaches to aid in fully understanding the heterogeneity of reactive astrocytes.