Figure 1.

Culturing mature brain slices at room temperature (24°C) and at 4°C “freezes” spines. A, Shown are single images taken from two time series of two dendrites in a mature hippocampal slice culture taken at the beginning (0) of a cooling period to 24°C and 190 min later (190). To the right, the corresponding motility images of time series are shown with areas of high motility in red and white and background motility in blue and black. Images were acquired every 15 sec. Initially, when the cultures were kept at 24°C, spines were still motile (left; 0 min); however, over time, spine motility disappeared (right; 190). Scale bar, 2 μm. B, Brief exposure (30 min) of mature slice culture to 4°C stops spine motility. Dendrites were imaged at 24°C, and the corresponding motility image is shown at the right. Note the small spines. Scale bar, 3 μm.