A single GABAergic neuron mediates feedback of odor-evoked signals in the mushroom body of larval Drosophila.

摘要: Inhibition has a central role in defining the selectivity of responses higher order neurons to sensory stimuli. However, circuit mechanisms regulation these by inhibitory are still unclear. In Drosophila, mushroom bodies (MBs) necessary for olfactory memory, and implication learned specific odors. To understand circuitry inhibition calyx (the input dendritic region) MBs, its relationship with MB excitatory activity, we used simple anatomy Drosophila larval system identify any inputs that could contribute odor responses. We found single neuron accounts all detectable GABA innervation this presynaptic terminals postsynaptic branches lobes (output axonal area). call anterior paired lateral (APL) neuron, because similarity previously described adult APL neuron. Reconstitution GFP partners (GRASP) suggests makes extensive contacts intrinsic neurons, Kenyon Cells (KCs), but few incoming projection neurons. Using calcium imaging neuronal activity live larvae, show responds odors, mannner requires output from KCs. Our data suggest is sole GABAergic innervates region carries feedback region, consistent modulating