Abstract: The cerebral cortex is one of the most complex structures of the mammalian central nervous system and accounts for the extraordinary cognitive abilities in primates and humans. Since the 19th century, neur ons have been believed to be the main players in the building of the brain, yet astrocytes also play a crucial role as fundamental building blocks of the cerebral cortex complexity. Currently, astrocytes are recognized as pivotal players in the central nervous system exerting a myriad of functions, such as water homeostasis and exchange of nutrients with the blood-brain barrier. Astrocytes also play a crucial role in the development and regulation of connectivity including synapse formation and elimination, and synaptic function and plasticity (Verkhratsky and Nedergaard, 2018). Furthermore, injury or stress induces reactive astrogliosis that provides antioxidant defense and scar formation. While astrocytes have been mostly studied in mice, we are becoming aware of astrocyte heterogeneity and increased complexity in mammals and primates (Oberheim et al., 2009; Falcone et al., 2019, 2020). Astrocytes likely co-evolved with neurons, becoming more specialized in mammals versus other vertebrates. Only recently attention has been put towards specific types of astrocytes in the primate brain. Understanding how astrocytes develop, evolve across mammalian species, and regulate neuronal development and function is crucial to understand the cerebral cortex complexity characteristic of human and nonhuman primates.