Together, these studies demonstrate that human astrocytes generated within the mouse brain maintain their complex phenotype in a cell-autonomous fashion; they assume morphologies and Ca2+ wave characteristics typical of the human brain, but hitherto never observed in experimental animals. These observations strongly support the notion that the evolution of human neural processing, and hence the species-specific aspects of human cognition, in part may reflect the course of astrocytic evolution (Oberheim et al., 2006). As such, these human glial-chimeric mice may present a fundamentally new experimental model by which human glial cells, and both normative and pathological species-specific aspects of human glial biology, may now be effectively studied in the live adult brain.
