Fig. 2.

Hub and Collective Influence map. a The giant (largest) connected component G (yellow) captures the integration of two modules into a brain network. b Influence of a hub and a CI node. Inactivation of the hub (white node) produces less damage to brain integration, measured by the size reduction of G, then the inactivation of the CI node (black). c Relative size of G as a function of the fraction of inactivated nodes, q. Two strategies are shown for choosing the essential nodes in a representative animal: Hub inactivation (triangles) and CI inactivation (circles). Nodes are removed one by one according to their degree or CI-score, respectively, from high to low. Colors refer to the nodes module (HC, NAc, or PFC, see legend). Most hubs (red symbols) are located in HC, yet, they are not essential for integration: their removal makes minimal damage to G. On the contrary, by inactivating 7% of high CI nodes, G collapses to almost zero. Most CI nodes are in the NAc (green symbols). d Representative brain network as in (c), displaying the PFC–HC–NAc networks. The size of each node is proportional to the CI score. e We inactivate the top 3% of high CI nodes (yellow circles) and G is drastically reduced to less than 40% of its original value. These top CI nodes are all in the NAc except for two nodes in the PFC. f Further inactivating up to 7% of the high CI nodes prevents integration of G. Yellow circles indicate the essential nodes, located mostly in the NAc shell. g Average hub map indicating top hub nodes over six animals. Yellow/white areas correspond to top essential nodes all located in the HC since this is the area of LTP induction. Color bar represents the average rank (Supplementary Eq. (8)). h Average CI map indicating top CI nodes over six animals, most CI nodes result in the NAc and are generally not hubs. Color bar is defined in Supplementary Eq. (8), the size bar corresponds to 0.5 mm