From origins to nomenclature: illuminating the landscape of CNS fibroblasts and fibroblast-like cells

Fibroblasts are a group of stromal cells that contribute to the scarring process in many neurological conditions in the central nervous system (CNS). Recently, single-cell sequencing efforts allowed an in-depth understanding of their cell origins and subpopulation profiles. Meanwhile, vascular leptomeningeal cells and the "type A pericytes" were also proposed as CNS fibroblast-like cells in the last decade by histological, functional and transcriptomic analysis. While these cells share overlapping features with CNS fibroblasts, the inconsistent use of nomenclature and partially overlapping cell-type markers is likely to cause confusion within the growing field of neurobiology. In this review, we will delineate the current knowledge of subtypes and functions of CNS fibroblasts, with special focus on the source of PVFs during development and the nomenclature origins of other similar cell types. We aim to provide comprehensive insights into these cells with similar functions or transcriptomic profiles.