Fig. 9.
The percentage of neurectoderm circus cells demonstrating elevation of [Ca2+]i in response to depolarization with 50 mm KCl increases with time in culture. Responses are detected in circus cells that subsequently differentiate into explicit neurons (shaded bars). An additional population of circus cells responds to KCl but later fails to differentiate morphologically (white bars), and a small population of round cells also responds to KCl challenge (black bars). An average of 30 cells from five cultures were sampled for each hour.