Astrocytes make up the majority of the cells in the mammalian brain. They are the most variable in type, most intimately associated with all parts of neurons, and thus most functionally interesting in their relationships with neurons. They provide structural, trophic, and metabolic support to neurons and modulate synaptic activity. Impairment of these astrocyte functions during stroke and other insults can critically influence neuron survival. Furthermore, astrocytes have been implicated in the pathological processes of many neurological diseases. Long-term recovery after brain injury, through neurite outgrowth, synaptic plasticity, or neuron regeneration, is influenced by astrocyte surface molecule expression and trophic factor release. In addition, the death or survival of astrocytes themselves may affect the ultimate clinical outcome. Recognition of the importance of astrocytes in nervous system functioning is increasing, specifically regarding the modulation of neural activity. Much of what we have learned about astrocytes is from the in vitro studies and astrocyte cultures are continuing to provide a useful tool in exploring the diverse property of these cells.HA-sp from AcceGen Biotech Research Laboratories are isolated from human spinal cord. HA-sp are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 10^5 cells in 1 ml volume. HA-sp are characterized by immunofluorescent method with antibody to GFAP. HA-sp are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HA-sp are guaranteed to further expand for 15 population doublings at the conditions provided by AcceGen Biotech Research Laboratories.