The Neuroanatomical Ultrastructure and Function of a Biological Ring Attractor - One color calcium imaging data

All one-color calcium imaging experiments of the ring neurons, R4d, are contained in this zip file. The directories are arranged first by cell type, then by the date of the experiment for that cell type. Each trial has its own .mat files, and each mat file features a matrix containing the raw DF/F signal at each time point for each region of interest (ROIaveMax) and a structure that contains the behavioral data (positionDat).
Neural representations of head direction (HD) have been discovered in many species. Theoretical work has proposed that the dynamics associated with these representations are generated, maintained, and updated by recurrent network structures called ring attractors. We evaluated this theorized structure-function relationship by performing electron-microscopy-based circuit reconstruction and RNA profiling of identified cell types in the HD system of Drosophila melanogaster. We identified motifs that have been hypothesized to maintain the HD representation in darkness, update it when the animal turns, and tether it to visual cues. Functional studies provided support for the proposed roles of individual excitatory or inhibitory circuit elements in shaping activity. We also discovered recurrent connections between neuronal arbors with mixed pre- and postsynaptic specializations. Our results confirm that the Drosophila HD network contains the core components of a ring attractor while also revealing unpredicted structural features that might enhance the network’s computational power.