Date of Completion
Graduate School of Biomedical Sciences, MD/PhD Program; Graduate School of Biomedical Sciences, Program in Neuroscience
Feeding is one of the most important behaviors for an animal’s survival. At a gross level, it is known that the nervous system plays a major role in the expression of this complex behavior, yet a detailed understanding of the neural circuits directing feeding behavior remains unknown. Here we identify a command neuron in Drosophila melanogaster whose artificial activation, using dTrpA1, a heat-activated cation channel, induces the appearance of complete feeding behavior. We use behavioral, genetic, cellular and optical imaging techniques to show that the induced behavior is composed of multiple motor programs and can function to uptake exogenous, even noxious, material. Furthermore, we resolve the neuron’s location to the subesophageal ganglion, characterize its pre and post-synaptic sites, and determine its responsiveness to sucrose stimulation. Interestingly, the neuron’s dendritic field is proximal to sweet sensing axon terminals and its baseline activity corresponds to the fly’s satiation state, suggesting a potential point of integration between sensory, motor and motivational systems. The identification of a command neuron for feeding in a genetically tractable organism provides a useful model to develop a deeper understanding of the neural control of this ubiquitous and evolutionarily ancient behavior.
Flood, Thomas F., "Identification of a Command Neuron Directing the Expression of Feeding Behavior in Drosophila melanogaster: A Dissertation" (2011). University of Massachusetts Medical School. GSBS Dissertations and Theses. Paper 523.
Rights and Permissions
Copyright is held by the author, with all rights reserved.
Wild-type behavior at 15°C.
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Trpm8-induced ‘Full Paralysis’.
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Trpm8-induced ‘Wing Beat Paralysis’.
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Trpm8-induced ‘Frozen Still Paralysis’.
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Trpm8-induced ‘Short Spasm’.
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Trpm8-induced ‘Wing Raising’.
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Trpm8-induced ‘Wing Clip’.
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Trpm8-induced ‘Wing Beat’.
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Trpm8-induced ‘Courtship Song’.
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Trpm8-induced ‘Courtship’ at 25°C.
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dTrpA1-induced ‘Wing Raise’.
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dTrpA1-induced ‘Egg Laying’.
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dTrpA1-induced ‘Egg Laying’ part 2.
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dTrpA1-induced ‘Abdominal Bending’.
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dTrpA1-induced ‘Feeding’ part 2.
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dTrpA1-induced ‘Initiation of Voluntary Flight’.
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dTrpA1-induced ‘Initiation of Voluntary Flight’ part 2.
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dTrpA1-induced ‘Initiation of Voluntary Flight’ part 3.
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dTrpA1-induced ‘Initiation of Voluntary Flight’ part 4.
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dTrpA1-induced ‘Crazy Leg Paralysis’.
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dTrpA1-induced ‘Wing Raise/Aggression’.
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dTrpA1-induced ‘Wing Raise/Aggression’ version 2.
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Wild-type feeding behavior of starved fly on food.
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dTrpA1-induced behavior closely resembles wild-type feeding behavior.
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NP5137-GAL4/uas-dTrpA1 induced behavior resembles natural feeding.
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Male NP-GAL4/uas-dTrpA1 flies display suction.
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Cibarial pump is activated and functioning.
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Behavior can be induced in unnatural contexts.
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Mosaic FC-neuron positive flies demonstrate the induction of multiple motor programs characteristic of wild-type feeding behavior.
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3-D movie of FC-neuron from mosaic fly showing predicted pre and post-synaptic compartments.
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Proboscis extension behavior during simultaneous calcium imaging.
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Flies expressing the kir2.1 channel appeared vigorous and healthy before testing.
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Positive proboscis extension (PE).
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Visualization of cibarial pump activity in wild-type flies.
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Dye Assay analysis at three points along the gastrointestinal tract.
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