The ProjectionStructureUnionize model in the connectivity atlas API summarizes projection signal for each experiment at a structural level. Computed parameters include: projection density (sum of detected pixels / sum of all pixels in a structure), projection energy (sum of detected pixel intensity / sum of all pixels in a structure), and projection volume (sum of detected pixels normalized to mm3). Refer to the informatics whitepaper for a more detailed description of the informatics processing pipeline.
This example demonstrates how to download projection volume values for a specific set of structures and experiments and visualizes them as a heatmap. The experiments chosen for this example have primary injections in seven different cortical regions (y axis). The target structures span the thalamus (x axis). Notice how the projection signal volume patterns differ significantly based on injection site.