Movies 1 through 3 illustrate different approaches to visualizing dynamic changes in fluorescence emission following stimulation of the Drosophila lateral protocerebral lobe with KCl using flies expressing the calcium sensor cameleon 2.1. All three movies present the same data, in which a contraction of the tissue is followed by a transient increase in intracellular calcium.

Movie 1. Pseudocolor-coded ratio of enhanced yellow fluorescent protein over enhanced cyan fluorescent protein (EYFP/ECFP) fluorescence. Movie 1 shows the pseudocolor-coded ratio of EYFP/ECFP emission, giving only a rough indication of morphological structures.	Color Scale Movie 1
Movie 2. Grayscale coding of EYFP/ECFP with pseudocolor applied at a threshold value above baseline. Movie 2 shows the same data as movie 1, but uses a different color scale. The ratio EYFP/ECFP is greyscale-coded, showing the morphology of the tissue. The increase in EYFP/ECFP ratio is visualized by applying a threshold above the averaged baseline ratio at which the scale is changed to a pseudocolor presentation with a very narrow color range.	Color Scale Movie 2
Movie 3. Averaged EYFP emissions in greyscale, with pseudocolored ratio above threshold superimposed. In Movie 3, which shows the same data as Movie 1 and Movie 2, the average of the greyscaled EYFP emissions is calculated, and the above-threshold pseudocolor-coded ratio is superimposed to indicate the increase in intracellular calcium concentration. Similar results are obtained as in Movie 2, with morphology indicated more clearly than in Movie 1.	Color Scale Movie 3

Citation: A. Fiala, T. Spall, In vivo calcium imaging of brain activity in Drosophila by transgenic cameleon expression. Sci. STKE 2003, pl6 (2003).

These movies are viewable using Quicktime, which can be downloaded from Apple's Quicktime site.