An open source tool for automatic spatiotemporal assessment of calcium transients and local ‘signal-close-to-noise’ activity in calcium imaging data
Fig 8
Parallel computing of activity events and variance area.
a, Activity map of spontaneous activity of hippocampal neurons (DIV 10) before and after acute activity blockade. b, Calcium spike formation (left trace) is blocked by the inhibitor cocktail (right trace). c—e, Raw traces representing typical calcium signals in non-spiking areas (black trace). The yellow band indicates the variance area in a sliding window of 30 images. Activity marks are indicated as red dots. The activity state of the grid windows is described with two parameters, the variance area, and the number of activity events. c, Signal trace with one or two computed activity events. The variance area is almost identical before and after spike block. d, Signal fluctuations, represented by the variance area, become smaller under spike block conditions. Furthermore, the activity inhibitor cocktail reduces the number of activity events. e, This grid window over a neuritic element shows high signal fluctuation, which correlates with a higher number of activity events. Spike-blockade reduces the variance area and the number of activity events. However, a local activity event is not blocked by the inhibitor cocktail. Structural elements of local activity on the basis of this analysis are shown in Fig 9.