Fig 1. Sleep homeostasis and navigation circuits in the central complex.

A: Recurrent sleep homeostasis circuit proposed in [18]. The three populations are connected via excitatory (green arrows) or inhibitory (red arrows) connections. Images are downloaded from the connectome database [14]. B: Interaction between the fly head direction circuit and populations involved in sleep homeostasis. C: Switch behavior of dFB neurons modeled with hysteresis. D: Simulation of the sleep homeostasis model illustrating the dynamics of each population over time. E: Schematic of connectivity between wedge neurons and R5 and ExR1 neurons in the ellipsoid body.