Fig. 2: Clustering of cells and cell types based on connectivity.
From: Neuronal parts list and wiring diagram for a visual system
a, Feature vectors for three example cells. The horizontal axis indicates the synapse numbers that the cell receives from presynaptic types (red region of vertical axis) and sends to postsynaptic types (green region of vertical axis). Cells 1 and 2 (same type) have more similar feature vectors to each other than to cell 3 (different type). The long numbers are the cell IDs in version 783 of the FlyWire connectome. b, Cells 1 and 2 (same type) are closer to each other than to cell 3 (a different type), according to the weighted Jaccard distances between the cell feature vectors. Such distances are the main basis for dividing cells into cell types (Methods). c, Dendrogram of cell types. Cell types that merge closer to the circumference are more similar to each other. Flat clustering (16 colours) is created by thresholding at 0.9. A few clusters containing single types (Lat, L3 and Lawf2) are uncoloured. To obtain the dendrogram, feature vectors of cells in each type were summed or averaged to yield a feature vector for that cell type, and then cell type feature vectors were hierarchically clustered using average linkage. Jaccard distances run from 0.4 (circumference) to 1 (centre). Clusters containing more than one cell type (legend with coloured lines) are numbered starting at ‘3 o’clock’ on the dendrogram and proceeding counterclockwise.
