Figure 8

Functional response of brain culture. Cells were cultured on PDL-coated glass coverslips. Approximately 100 regions of interest (ROI) s were selected indiscriminately. The coverslips are loaded with Fura-2 dye and placed in standard extracellular solution (see methods). After depolarization with 70 mM KCl, another wash with standard extracellular solution is utilized to eliminate dead cells. The trace shown represents an average (3 experiments) of all cells that respond to KCl and the second wash. It is important to note that there were cells that did not respond to KCl which could be dead cells or non-neuronal cells. Fura emits at two wavelengths - 340 nm and 380 nm [26] and the ratio of these corresponds to the intracellular calcium. All three points show a calcium response after induced depolarization, suggesting that these are functionally active neurons.