title: Astrocytic complexity distinguishes the human brain.
abstract: One of the most distinguishing features of the adult human brain is the complexity and diversity of its cortical astrocytes. Human protoplasmic astrocytes manifest a threefold larger diameter and have tenfold more primary processes than those of rodents. In all mammals, protoplasmic astrocytes are organized into spatially non-overlapping domains that encompass both neurons and vasculature. Yet unique to humans and primates are additional populations of layer 1 interlaminar astrocytes that extend long (millimeter) fibers, and layer 5-6 polarized astrocytes that also project distinctive long processes. We propose that human cortical evolution has been accompanied by increasing complexity in the form and function of astrocytes, which reflects an expansion of their functional roles in synaptic modulation and cortical circuitry.
authors.affiliation: Center for Aging and Developmental Biology, Department of Neurosurgery, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA.
authors.forename: Nancy Ann
authors.initials: NA
authors.lastname: Oberheim
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Wang
authors.forename: Steven
authors.initials: S
authors.lastname: Goldman
authors.forename: Maiken
authors.initials: M
authors.lastname: Nedergaard
mesh_terms: D000328:Adult; D000818:Animals; D001253:Astrocytes / Q000166:cytology*; D005075:Biological Evolution; D001921:Brain / Q000166:cytology*; D006801:Humans