Figure 75. The central complex (CX) seen as a deep recurrent neural network for navigation.

(A) A layered representation of the connectivity of a selection of neuron types in the CX, with a bias towards those involved in navigation. Layers have been labeled by their putative computational roles in a navigational context. (B) The connectivity of ER4m, ER3a_a,d, ER3m, ER4d, ER2_a,b,d, ER1_a,b, and EPG neurons is densely recurrent. However, different neuron types have specific roles in circuit function. The ER types plotted here are also the types plotted in layer 2 (cue competition/stimulus selection) in (A). (C) If neurons in (B) were unsorted, the structure in their connectivity would be difficult to recognize (left). When properly sorted by types, the structure in the network connectivity becomes clear (right). The neuron names were randomly shuffled to generate the unsorted plot at left.

Figure 75—figure supplement 1. The structure in the fan-shaped body (FB) connectivity becomes clear when neurons are sorted by type.

As in Figure 75C, but now for the neurons in layers 4-7 (vector computations/coordinate transformations, action selection) of Figure 75A.