FIGURE 1.

Cell viability in cultured slices from ex vivo adult human cortex. After 25 days in vitro, slices were incubated with calcein and ethidium homodimer and imaged. A–C, representative images of a slice. A, bright field. Scale bar: 400 nm. B, ethidium homodimer + DAPI merged image. C, calcein + ethidium homodimer merged image. Dead cells can be readily identified among total (DAPI-stained) cells by red ethidium homodimer staining (B), in contrast with green calcein fluorescence emitted by live cells (C). D, cell viability in slices obtained from a single donor. Viability averaged 62 ± 1.4% for this particular experiment. E, no significant reduction in viability was noted after several days in culture using slices prepared from three different donors. F, immunohistochemistry of slices after 4 days in culture showing neurons (green, labeled using neuronal marker NeuN) and astroglial cells (red, labeled using anti-GFAP antibody). Scale bar: 40 nm. Semiquantitative analysis of cell types in slices from three different donors revealed an average of 60% neurons and 21% GFAP-positive cells in cortical human slices cultured for 4 days.