Fig. 3.

Construction principles of the network connectivity. a Each neuron receives four different types of connections. I: Intra-area synapses from within the $1{\mathrm{mm}}^2$ patch, II: Intra-area synapses from outside the $1{\mathrm{mm}}^2$ patch, III: Cortico-cortical synapses from vision-related areas, IV: Synapses from subcortical and non-visual cortical areas. b Average number of synapses per neuron across the 32 areas of the network versus overall neuron density. The dashed line shows the average indegree across all neurons of the network