What does the % in DF/F mean in the heatmap of tuning curve

Hi all,

I’m trying to pull out the neurons tuning curve to the drifting grating stimulus from Allensdk, and I get the heatmap but get confused about the DF/F %, maybe this is a very nuance question. But I would be very grateful if anyone knows what does the % sign mean? The value for heatmap ranges from -5 all the way to 12%, but the dff value for single neuron is only ranging from -1 to +1.

DF/F is computed relative to a baseline. For the tuning curve for a stimulus, the DF/F is computed for each trial using the mean fluorescence during the 1 second prior to the trial as the baseline. This is computed as a percentage. See Figure 5 in the “Stimulus Set and Response Analysis” documentation here: http://help.brain-map.org/display/observatory/Documentation

We also compute a “global” DF/F trace for each cell for the entire session which is accessible via the SDK. This uses a longer baseline, using the median fluorescence across a sliding 3 minute window. This is computed as a fraction.