Dissociation procedure for the extraction of astrocytes from neonatal and adult brain. Tissue from neonatal (A) and adult (B) brain was mechanically dissociated in the presence of papain (P), collagenase II (C), dispase II (D) or no enzymes (NE); and further purified through a 30 % Percoll gradient. Representative flow cytometry plots are shown. Astrocytes were identified as ACSA-2+ cells (gate). Cell death was measured after DAPI staining. Associated graphs correspond to % of astrocytes and astrocyte death. Data are expressed as mean ± S.E.M. (n = 3–4). *, p < 0.05; **, p < 0.01; ***, p < 0.001.