A Hard-Wired Glutamatergic Circuit Pools and Relays UV Signals to Mediate Spectral Preference in Drosophila

摘要: Summary Many visual animals have innate preferences for particular wavelengths of light, which can be modified by learning. Drosophila 's preference UV over visible light requires UV-sensing R7 photoreceptors and specific wide-field amacrine neurons called Dm8. Here we identify three types medulla projection downstream Dm8 show that selectively inactivating one them (Tm5c) abolishes preference. Using a GRASP method to probe synaptic connections at the single-cell level, reveal each neuron forms multiple contacts with Tm5c in center Dm8's dendritic field but sparse periphery. By transcript profiling RNAi-mediated knockdown, determine uses kainate receptor Clumsy receive excitatory glutamate input from We conclude R7s→Dm8→Tm5c form hard-wired glutamatergic circuit mediates pooling ∼16 signals transfer lobula, higher center. Video Abstract