201
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Crossley M, Staras K, Kemenes G. A two-neuron system for adaptive goal-directed decision-making in Lymnaea. Nat Commun 2016; 7:11793. [PMID: 27257106 PMCID: PMC4895806 DOI: 10.1038/ncomms11793] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 04/28/2016] [Indexed: 11/30/2022] Open
Abstract
During goal-directed decision-making, animals must integrate information from the external environment and their internal state to maximize resource localization while minimizing energy expenditure. How this complex problem is solved by the nervous system remains poorly understood. Here, using a combined behavioural and neurophysiological approach, we demonstrate that the mollusc Lymnaea performs a sophisticated form of decision-making during food-searching behaviour, using a core system consisting of just two neuron types. The first reports the presence of food and the second encodes motivational state acting as a gain controller for adaptive behaviour in the absence of food. Using an in vitro analogue of the decision-making process, we show that the system employs an energy management strategy, switching between a low- and high-use mode depending on the outcome of the decision. Our study reveals a parsimonious mechanism that drives a complex decision-making process via regulation of levels of tonic inhibition and phasic excitation. Integrating information from both the external environment and an organism's internal state is an important aspect of feeding-related decision making. Here, the authors identify a two neuron circuit within the mollusc Lymnaea that adapts feeding behaviour according to food availability and motivational state.
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Affiliation(s)
- Michael Crossley
- Sussex Neuroscience, School of Life Sciences, University of Sussex, 1 Lewes Road, Brighton BN1 9QG, UK
| | - Kevin Staras
- Sussex Neuroscience, School of Life Sciences, University of Sussex, 1 Lewes Road, Brighton BN1 9QG, UK
| | - György Kemenes
- Sussex Neuroscience, School of Life Sciences, University of Sussex, 1 Lewes Road, Brighton BN1 9QG, UK
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202
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Cervantes-Sandoval I, Chakraborty M, MacMullen C, Davis RL. Scribble Scaffolds a Signalosome for Active Forgetting. Neuron 2016; 90:1230-1242. [PMID: 27263975 DOI: 10.1016/j.neuron.2016.05.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 03/24/2016] [Accepted: 04/25/2016] [Indexed: 12/13/2022]
Abstract
Forgetting, one part of the brain's memory management system, provides balance to the encoding and consolidation of new information by removing unused or unwanted memories or by suppressing their expression. Recent studies identified the small G protein, Rac1, as a key player in the Drosophila mushroom bodies neurons (MBn) for active forgetting. We subsequently discovered that a few dopaminergic neurons (DAn) that innervate the MBn mediate forgetting. Here we show that Scribble, a scaffolding protein known primarily for its role as a cell polarity determinant, orchestrates the intracellular signaling for normal forgetting. Knocking down scribble expression in either MBn or DAn impairs normal memory loss. Scribble interacts physically and genetically with Rac1, Pak3, and Cofilin within MBn, nucleating a forgetting signalosome that is downstream of dopaminergic inputs that regulate forgetting. These results bind disparate molecular players in active forgetting into a single signaling pathway: Dopamine→ Dopamine Receptor→ Scribble→ Rac→ Cofilin.
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Affiliation(s)
| | - Molee Chakraborty
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Courtney MacMullen
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA.
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203
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Webb B, Wystrach A. Neural mechanisms of insect navigation. CURRENT OPINION IN INSECT SCIENCE 2016; 15:27-39. [PMID: 27436729 DOI: 10.1016/j.cois.2016.02.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/16/2016] [Accepted: 02/22/2016] [Indexed: 06/06/2023]
Abstract
We know more about the ethology of insect navigation than the neural substrates. Few studies have shown direct effects of brain manipulation on navigational behaviour; or measure brain responses that clearly relate to the animal's current location or spatial target, independently of specific sensory cues. This is partly due to the methodological problems of obtaining neural data in a naturally behaving animal. However, substantial indirect evidence, such as comparative anatomy and knowledge of the neural circuits that provide relevant sensory inputs provide converging arguments for the role of some specific brain areas: the mushroom bodies; and the central complex. Finally, modelling can help bridge the gap by relating the computational requirements of a given navigational task to the type of computation offered by different brain areas.
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Affiliation(s)
- Barbara Webb
- School of Informatics, University of Edinburgh, 10 Crichton St, Edinburgh EH8 9AB, UK.
| | - Antoine Wystrach
- Centre de Recherches sur la Cognition Animale, Centre National de la Recherche Scientifique, Universite Paul Sabatier, Toulouse, France
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204
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Owald D, Lin S, Waddell S. Light, heat, action: neural control of fruit fly behaviour. Philos Trans R Soc Lond B Biol Sci 2016; 370:20140211. [PMID: 26240426 PMCID: PMC4528823 DOI: 10.1098/rstb.2014.0211] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The fruit fly Drosophila melanogaster has emerged as a popular model to investigate fundamental principles of neural circuit operation. The sophisticated genetics and small brain permit a cellular resolution understanding of innate and learned behavioural processes. Relatively recent genetic and technical advances provide the means to specifically and reproducibly manipulate the function of many fly neurons with temporal resolution. The same cellular precision can also be exploited to express genetically encoded reporters of neural activity and cell-signalling pathways. Combining these approaches in living behaving animals has great potential to generate a holistic view of behavioural control that transcends the usual molecular, cellular and systems boundaries. In this review, we discuss these approaches with particular emphasis on the pioneering studies and those involving learning and memory.
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Affiliation(s)
- David Owald
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Suewei Lin
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
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205
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Perisse E, Owald D, Barnstedt O, Talbot CB, Huetteroth W, Waddell S. Aversive Learning and Appetitive Motivation Toggle Feed-Forward Inhibition in the Drosophila Mushroom Body. Neuron 2016; 90:1086-99. [PMID: 27210550 PMCID: PMC4893166 DOI: 10.1016/j.neuron.2016.04.034] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 03/27/2016] [Accepted: 04/19/2016] [Indexed: 11/23/2022]
Abstract
In Drosophila, negatively reinforcing dopaminergic neurons also provide the inhibitory control of satiety over appetitive memory expression. Here we show that aversive learning causes a persistent depression of the conditioned odor drive to two downstream feed-forward inhibitory GABAergic interneurons of the mushroom body, called MVP2, or mushroom body output neuron (MBON)-γ1pedc>α/β. However, MVP2 neuron output is only essential for expression of short-term aversive memory. Stimulating MVP2 neurons preferentially inhibits the odor-evoked activity of avoidance-directing MBONs and odor-driven avoidance behavior, whereas their inhibition enhances odor avoidance. In contrast, odor-evoked activity of MVP2 neurons is elevated in hungry flies, and their feed-forward inhibition is required for expression of appetitive memory at all times. Moreover, imposing MVP2 activity promotes inappropriate appetitive memory expression in food-satiated flies. Aversive learning and appetitive motivation therefore toggle alternate modes of a common feed-forward inhibitory MVP2 pathway to promote conditioned odor avoidance or approach. Aversive learning reduces odor-specific feed-forward inhibition in mushroom body Feed-forward inhibition selectively inhibits avoidance-directing neural pathways Appetitive motivation increases feed-forward inhibition in the mushroom body Imposing feed-forward inhibition favors appetitive memory expression
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Affiliation(s)
- Emmanuel Perisse
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - David Owald
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - Oliver Barnstedt
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - Clifford B Talbot
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - Wolf Huetteroth
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK.
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206
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Crocker A, Guan XJ, Murphy CT, Murthy M. Cell-Type-Specific Transcriptome Analysis in the Drosophila Mushroom Body Reveals Memory-Related Changes in Gene Expression. Cell Rep 2016; 15:1580-1596. [PMID: 27160913 DOI: 10.1016/j.celrep.2016.04.046] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 02/21/2016] [Accepted: 04/08/2016] [Indexed: 12/25/2022] Open
Abstract
Learning and memory formation in Drosophila rely on a network of neurons in the mushroom bodies (MBs). Whereas numerous studies have delineated roles for individual cell types within this network in aspects of learning or memory, whether or not these cells can also be distinguished by the genes they express remains unresolved. In addition, the changes in gene expression that accompany long-term memory formation within the MBs have not yet been studied by neuron type. Here, we address both issues by performing RNA sequencing on single cell types (harvested via patch pipets) within the MB. We discover that the expression of genes that encode cell surface receptors is sufficient to identify cell types and that a subset of these genes, required for sensory transduction in peripheral sensory neurons, is not only expressed within individual neurons of the MB in the central brain, but is also critical for memory formation.
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Affiliation(s)
- Amanda Crocker
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Xiao-Juan Guan
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Coleen T Murphy
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Paul F. Glenn Laboratories for Aging Research, Princeton University, Princeton, NJ 08544, USA
| | - Mala Murthy
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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207
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Erion R, King AN, Wu G, Hogenesch JB, Sehgal A. Neural clocks and Neuropeptide F/Y regulate circadian gene expression in a peripheral metabolic tissue. eLife 2016; 5. [PMID: 27077948 PMCID: PMC4862751 DOI: 10.7554/elife.13552] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 04/07/2016] [Indexed: 11/23/2022] Open
Abstract
Metabolic homeostasis requires coordination between circadian clocks in different tissues. Also, systemic signals appear to be required for some transcriptional rhythms in the mammalian liver and the Drosophila fat body. Here we show that free-running oscillations of the fat body clock require clock function in the PDF-positive cells of the fly brain. Interestingly, rhythmic expression of the cytochrome P450 transcripts, sex-specific enzyme 1 (sxe1) and Cyp6a21, which cycle in the fat body independently of the local clock, depends upon clocks in neurons expressing neuropeptide F (NPF). NPF signaling itself is required to drive cycling of sxe1 and Cyp6a21 in the fat body, and its mammalian ortholog, Npy, functions similarly to regulate cycling of cytochrome P450 genes in the mouse liver. These data highlight the importance of neuronal clocks for peripheral rhythms, particularly in a specific detoxification pathway, and identify a novel and conserved role for NPF/Npy in circadian rhythms. DOI:http://dx.doi.org/10.7554/eLife.13552.001 Many processes in the body follow rhythms that repeat over 24 hours and are synchronized to the cycle of day and night. Our sleep pattern is a well-known example, but others include daily fluctuations in body temperature and the production of several hormones. Internal clocks located in the brain and other organs drive these rhythms by altering the activity of certain genes depending on the time of day. Animals have specific organs that contain enzymes needed to break down toxic molecules in the body, and the levels of several of these enzymes rise and fall over each 24-hour period. In mammals, these enzymes are found in the liver, but in insects they are found in an organ called the fat body. Here, Erion, King et al. set out to determine the extent to which the internal clock in the brain influences the daily rhythms of these enzymes. The experiments show that a hormone released by the nervous system is required for the levels of the detoxifying enzymes to change in 24-hour cycles. This hormone – termed Neuropeptide F in fruit flies and Neuropeptide Y in mice – is also known to stimulate both mice and fruit flies to eat. Since toxic molecules often enter the body during feeding, Erion, King et al. speculate that it may be beneficial to link the detoxification process to feeding by using the same mechanism to control both processes. The next step following on from this work would be to find out exactly how neuropeptide F drives the 24-hour rhythms in the fat body and other organs. DOI:http://dx.doi.org/10.7554/eLife.13552.002
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Affiliation(s)
- Renske Erion
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, United States
| | - Anna N King
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, United States
| | - Gang Wu
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, United States
| | - John B Hogenesch
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, United States
| | - Amita Sehgal
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, United States
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208
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Hige T, Aso Y, Modi MN, Rubin GM, Turner GC. Heterosynaptic Plasticity Underlies Aversive Olfactory Learning in Drosophila. Neuron 2016; 88:985-998. [PMID: 26637800 DOI: 10.1016/j.neuron.2015.11.003] [Citation(s) in RCA: 219] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 09/11/2015] [Accepted: 10/14/2015] [Indexed: 11/16/2022]
Abstract
Although associative learning has been localized to specific brain areas in many animals, identifying the underlying synaptic processes in vivo has been difficult. Here, we provide the first demonstration of long-term synaptic plasticity at the output site of the Drosophila mushroom body. Pairing an odor with activation of specific dopamine neurons induces both learning and odor-specific synaptic depression. The plasticity induction strictly depends on the temporal order of the two stimuli, replicating the logical requirement for associative learning. Furthermore, we reveal that dopamine action is confined to and distinct across different anatomical compartments of the mushroom body lobes. Finally, we find that overlap between sparse representations of different odors defines both stimulus specificity of the plasticity and generalizability of associative memories across odors. Thus, the plasticity we find here not only manifests important features of associative learning but also provides general insights into how a sparse sensory code is read out.
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Affiliation(s)
- Toshihide Hige
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Mehrab N Modi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Glenn C Turner
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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209
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Barnstedt O, Owald D, Felsenberg J, Brain R, Moszynski JP, Talbot CB, Perrat PN, Waddell S. Memory-Relevant Mushroom Body Output Synapses Are Cholinergic. Neuron 2016; 89:1237-1247. [PMID: 26948892 PMCID: PMC4819445 DOI: 10.1016/j.neuron.2016.02.015] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 01/04/2016] [Accepted: 01/27/2016] [Indexed: 11/17/2022]
Abstract
Memories are stored in the fan-out fan-in neural architectures of the mammalian cerebellum and hippocampus and the insect mushroom bodies. However, whereas key plasticity occurs at glutamatergic synapses in mammals, the neurochemistry of the memory-storing mushroom body Kenyon cell output synapses is unknown. Here we demonstrate a role for acetylcholine (ACh) in Drosophila. Kenyon cells express the ACh-processing proteins ChAT and VAChT, and reducing their expression impairs learned olfactory-driven behavior. Local ACh application, or direct Kenyon cell activation, evokes activity in mushroom body output neurons (MBONs). MBON activation depends on VAChT expression in Kenyon cells and is blocked by ACh receptor antagonism. Furthermore, reducing nicotinic ACh receptor subunit expression in MBONs compromises odor-evoked activation and redirects odor-driven behavior. Lastly, peptidergic corelease enhances ACh-evoked responses in MBONs, suggesting an interaction between the fast- and slow-acting transmitters. Therefore, olfactory memories in Drosophila are likely stored as plasticity of cholinergic synapses. Mushroom body Kenyon cell function requires ChAT and VAChT expression Kenyon cell-released acetylcholine drives mushroom body output neurons Blocking nicotinic receptors impairs mushroom body output neuron activation Acetylcholine interacts with coreleased neuropeptide
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Affiliation(s)
- Oliver Barnstedt
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - David Owald
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
| | - Johannes Felsenberg
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Ruth Brain
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - John-Paul Moszynski
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Clifford B Talbot
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Paola N Perrat
- Department of Neurobiology, UMass Medical School, Worcester, MA 01605, USA
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
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210
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Landayan D, Wolf FW. Shared neurocircuitry underlying feeding and drugs of abuse in Drosophila. Biomed J 2016; 38:496-509. [PMID: 27013449 PMCID: PMC6138758 DOI: 10.1016/j.bj.2016.01.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/13/2015] [Indexed: 01/06/2023] Open
Abstract
The neural circuitry and molecules that control the rewarding properties of food and drugs of abuse appear to partially overlap in the mammalian brain. This has raised questions about the extent of the overlap and the precise role of specific circuit elements in reward and in other behaviors associated with feeding regulation and drug responses. The much simpler brain of invertebrates including the fruit fly Drosophila, offers an opportunity to make high-resolution maps of the circuits and molecules that govern behavior. Recent progress in Drosophila has revealed not only some common substrates for the actions of drugs of abuse and for the regulation of feeding, but also a remarkable level of conservation with vertebrates for key neuromodulatory transmitters. We speculate that Drosophila may serve as a model for distinguishing the neural mechanisms underlying normal and pathological motivational states that will be applicable to mammals.
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Affiliation(s)
- Dan Landayan
- Department of Molecular Cell Biology, School of Natural Sciences, University of California, Merced, CA, USA.
| | - Fred W Wolf
- Department of Molecular Cell Biology, School of Natural Sciences, University of California, Merced, CA, USA.
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211
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Das G, Lin S, Waddell S. Remembering Components of Food in Drosophila. Front Integr Neurosci 2016; 10:4. [PMID: 26924969 PMCID: PMC4759284 DOI: 10.3389/fnint.2016.00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 01/25/2016] [Indexed: 12/28/2022] Open
Abstract
Remembering features of past feeding experience can refine foraging and food choice. Insects can learn to associate sensory cues with components of food, such as sugars, amino acids, water, salt, alcohol, toxins and pathogens. In the fruit fly Drosophila some food components activate unique subsets of dopaminergic neurons (DANs) that innervate distinct functional zones on the mushroom bodies (MBs). This architecture suggests that the overall dopaminergic neuron population could provide a potential cellular substrate through which the fly might learn to value a variety of food components. In addition, such an arrangement predicts that individual component memories reside in unique locations. DANs are also critical for food memory consolidation and deprivation-state dependent motivational control of the expression of food-relevant memories. Here, we review our current knowledge of how nutrient-specific memories are formed, consolidated and specifically retrieved in insects, with a particular emphasis on Drosophila.
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Affiliation(s)
- Gaurav Das
- Centre for Neural Circuits and Behaviour, University of OxfordOxford, UK
| | - Suewei Lin
- Centre for Neural Circuits and Behaviour, University of OxfordOxford, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of OxfordOxford, UK
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212
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213
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Haberkern H, Jayaraman V. Studying small brains to understand the building blocks of cognition. Curr Opin Neurobiol 2016; 37:59-65. [PMID: 26826948 DOI: 10.1016/j.conb.2016.01.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 01/12/2016] [Indexed: 01/09/2023]
Abstract
Cognition encompasses a range of higher-order mental processes, such as attention, working memory, and model-based decision-making. These processes are thought to involve the dynamic interaction of multiple central brain regions. A mechanistic understanding of such computations requires not only monitoring and manipulating specific neural populations during behavior, but also knowing the connectivity of the underlying circuitry. These goals are experimentally challenging in mammals, but are feasible in numerically simpler insect brains. In Drosophila melanogaster in particular, genetic tools enable precisely targeted physiology and optogenetics in actively behaving animals. In this article we discuss how these advantages are increasingly being leveraged to study abstract neural representations and sensorimotor computations that may be relevant for cognition in both insects and mammals.
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Affiliation(s)
- Hannah Haberkern
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Vivek Jayaraman
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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214
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Yang CY, Yu K, Wang Y, Chen SA, Liu DD, Wang ZY, Su YN, Yang SZ, Chen TT, Livnat I, Vilim FS, Cropper EC, Weiss KR, Sweedler JV, Jing J. Aplysia Locomotion: Network and Behavioral Actions of GdFFD, a D-Amino Acid-Containing Neuropeptide. PLoS One 2016; 11:e0147335. [PMID: 26796097 PMCID: PMC4721866 DOI: 10.1371/journal.pone.0147335] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 01/01/2016] [Indexed: 12/02/2022] Open
Abstract
One emerging principle is that neuromodulators, such as neuropeptides, regulate multiple behaviors, particularly motivated behaviors, e.g., feeding and locomotion. However, how neuromodulators act on multiple neural networks to exert their actions remains poorly understood. These actions depend on the chemical form of the peptide, e.g., an alternation of L- to D- form of an amino acid can endow the peptide with bioactivity, as is the case for the Aplysia peptide GdFFD (where dF indicates D-phenylalanine). GdFFD has been shown to act as an extrinsic neuromodulator in the feeding network, while the all L-amino acid form, GFFD, was not bioactive. Given that both GdFFD/GFFD are also present in pedal neurons that mediate locomotion, we sought to determine whether they impact locomotion. We first examined effects of both peptides on isolated ganglia, and monitored fictive programs using the parapedal commissural nerve (PPCN). Indeed, GdFFD was bioactive and GFFD was not. GdFFD increased the frequency with which neural activity was observed in the PPCN. In part, there was an increase in bursting spiking activity that resembled fictive locomotion. Additionally, there was significant activity between bursts. To determine how the peptide-induced activity in the isolated CNS is translated into behavior, we recorded animal movements, and developed a computer program to automatically track the animal and calculate the path of movement and velocity of locomotion. We found that GdFFD significantly reduced locomotion and induced a foot curl. These data suggest that the increase in PPCN activity observed in the isolated CNS during GdFFD application corresponds to a reduction, rather than an increase, in locomotion. In contrast, GFFD had no effect. Thus, our study suggests that GdFFD may act as an intrinsic neuromodulator in the Aplysia locomotor network. More generally, our study indicates that physiological and behavioral analyses should be combined to evaluate peptide actions.
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Affiliation(s)
- Chao-Yu Yang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Ke Yu
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Ye Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Song-An Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Dan-Dan Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Zheng-Yang Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Yan-Nan Su
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Shao-Zhong Yang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Ting-Ting Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Itamar Livnat
- Beckman Institute for Advanced Science and Technology and Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Ferdinand S. Vilim
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Elizabeth C. Cropper
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Klaudiusz R. Weiss
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jonathan V. Sweedler
- Beckman Institute for Advanced Science and Technology and Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jian Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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215
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ICHINOSE T, TANIMOTO H. Dynamics of memory-guided choice behavior in Drosophila. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2016; 92:346-357. [PMID: 27725473 PMCID: PMC5243950 DOI: 10.2183/pjab.92.346] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
Memory retrieval requires both accuracy and speed. Olfactory learning of the fruit fly Drosophila melanogaster serves as a powerful model system to identify molecular and neuronal substrates of memory and memory-guided behavior. The behavioral expression of olfactory memory has traditionally been tested as a conditioned odor response in a simple T-maze, which measures the result, but not the speed, of odor choice. Here, we developed multiplexed T-mazes that allow video recording of the choice behavior. Automatic fly counting in each arm of the maze visualizes choice dynamics. Using this setup, we show that the transient blockade of serotonergic neurons slows down the choice, while leaving the eventual choice intact. In contrast, activation of the same neurons impairs the eventual performance leaving the choice speed unchanged. Our new apparatus contributes to elucidating how the speed and the accuracy of memory retrieval are implemented in the fly brain.
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Affiliation(s)
- Toshiharu ICHINOSE
- Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Max-Planck Institut für Neurobiologie, Martinsried, Germany
| | - Hiromu TANIMOTO
- Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Max-Planck Institut für Neurobiologie, Martinsried, Germany
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216
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Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory. Proc Natl Acad Sci U S A 2015; 112:E6663-72. [PMID: 26627257 DOI: 10.1073/pnas.1512792112] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-β'1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts.
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217
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Owald D, Waddell S. Olfactory learning skews mushroom body output pathways to steer behavioral choice in Drosophila. Curr Opin Neurobiol 2015; 35:178-84. [PMID: 26496148 PMCID: PMC4835525 DOI: 10.1016/j.conb.2015.10.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/29/2015] [Accepted: 10/05/2015] [Indexed: 11/18/2022]
Abstract
Learning permits animals to attach meaning and context to sensory stimuli. How this information is coded in neural networks in the brain, and appropriately retrieved and utilized to guide behavior, is poorly understood. In the fruit fly olfactory memories of particular value are represented within sparse populations of odor-activated Kenyon cells (KCs) in the mushroom body ensemble. During learning reinforcing dopaminergic neurons skew the mushroom body network by driving zonally restricted plasticity at synaptic junctions between the KCs and subsets of the overall small collection of mushroom body output neurons. Reactivation of this skewed KC-output neuron network retrieves memory of odor valence and guides appropriate approach or avoidance behavior.
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Affiliation(s)
- David Owald
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
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218
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Abstract
In mammals, evidence for memory reactivation during sleep highlighted the important role that sleep plays in memory consolidation. A new study reports that memory reactivation is evolutionarily conserved and can also be found in the honeybee.
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Affiliation(s)
- Krishna Melnattur
- Department of Anatomy & Neurobiology, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri 63110, USA
| | - Stephane Dissel
- Department of Anatomy & Neurobiology, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri 63110, USA
| | - Paul J Shaw
- Department of Anatomy & Neurobiology, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri 63110, USA.
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219
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Siju KP, Bräcker LB, Grunwald Kadow IC. Neural mechanisms of context-dependent processing of CO2 avoidance behavior in fruit flies. Fly (Austin) 2015; 8:68-74. [PMID: 25483251 DOI: 10.4161/fly.28000] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The fruit fly, Drosophila melanogaster, innately avoids even low levels of CO2. CO2 is part of the so-called Drosophila stress odor produced by stressed flies, but also a byproduct of fermenting fruit, a main food source, making the strong avoidance behavior somewhat surprising. Therefore, we addressed whether feeding states might influence the fly's behavior and processing of CO2. In a recent report, we showed that this innate behavior is differentially processed and modified according to the feeding state of the fly. Interestingly, we found that hungry flies require the function of the mushroom body, a higher brain center required for olfactory learning and memory, but thought to be dispensable for innate olfactory behaviors. In addition, we anatomically and functionally characterized a novel bilateral projection neuron connecting the CO2 sensory input to the mushroom body. This neuron was essential for processing of CO2 in the starved fly but not in the fed fly. In this Extra View article, we provide evidence for the potential involvement of the neuromodulator dopamine in state-dependent CO2 avoidance behavior. Taken together, our work demonstrates that CO2 avoidance behavior is mediated by alternative neural pathways in a context-dependent manner. Furthermore, it shows that the mushroom body is not only involved in processing of learned olfactory behavior, as previously suggested, but also in context-dependent innate olfaction.
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Affiliation(s)
- K P Siju
- a Sensory Neurogenetics Group; Max-Planck Institute of Neurobiology; Martinsried, Germany
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220
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Abstract
Sensory cues that predict reward or punishment are fundamental drivers of animal behavior. For example, attractive odors of palatable food or a potential mate predict reward, while aversive odors of pathogen-laced food or a predator predict punishment. Aversive and attractive odors can be detected by intermingled sensory neurons that express highly related olfactory receptors and display similar central projections. These findings raise basic questions of how innate odor valence is extracted from olfactory circuits, how such circuits are developmentally endowed and modulated by state, and how innate and learned odor responses are related. Here, we review odors, receptors and neural circuits associated with stimulus valence, discussing salient principles derived from studies on nematodes, insects and vertebrates. Understanding the organization of neural circuitry that mediates odor aversion and attraction will provide key insights into how the brain functions.
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221
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Albin S, Kaun K, Knapp JM, Chung P, Heberlein U, Simpson J. A Subset of Serotonergic Neurons Evokes Hunger in Adult Drosophila. Curr Biol 2015; 25:2435-40. [DOI: 10.1016/j.cub.2015.08.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 07/01/2015] [Accepted: 08/04/2015] [Indexed: 01/18/2023]
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222
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Rohwedder A, Selcho M, Chassot B, Thum AS. Neuropeptide F neurons modulate sugar reward during associative olfactory learning ofDrosophilalarvae. J Comp Neurol 2015; 523:2637-64. [DOI: 10.1002/cne.23873] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 07/19/2015] [Accepted: 07/28/2015] [Indexed: 01/29/2023]
Affiliation(s)
- Astrid Rohwedder
- Department of Biology; University of Fribourg; Fribourg Switzerland
| | - Mareike Selcho
- Department of Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter; University of Würzburg; Würzburg Germany
| | - Bérénice Chassot
- Department of Biology; University of Fribourg; Fribourg Switzerland
| | - Andreas S. Thum
- Department of Biology; University of Fribourg; Fribourg Switzerland
- Department of Biology; University of Konstanz; Konstanz Germany
- Zukunftskolleg; University of Konstanz; Konstanz Germany
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223
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Rhomboid Enhancer Activity Defines a Subset of Drosophila Neural Precursors Required for Proper Feeding, Growth and Viability. PLoS One 2015; 10:e0134915. [PMID: 26252385 PMCID: PMC4529294 DOI: 10.1371/journal.pone.0134915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 07/15/2015] [Indexed: 11/19/2022] Open
Abstract
Organismal growth regulation requires the interaction of multiple metabolic, hormonal and neuronal pathways. While the molecular basis for many of these are well characterized, less is known about the developmental origins of growth regulatory structures and the mechanisms governing control of feeding and satiety. For these reasons, new tools and approaches are needed to link the specification and maturation of discrete cell populations with their subsequent regulatory roles. In this study, we characterize a rhomboid enhancer element that selectively labels four Drosophila embryonic neural precursors. These precursors give rise to the hypopharyngeal sensory organ of the peripheral nervous system and a subset of neurons in the deutocerebral region of the embryonic central nervous system. Post embryogenesis, the rhomboid enhancer is active in a subset of cells within the larval pharyngeal epithelium. Enhancer-targeted toxin expression alters the morphology of the sense organ and results in impaired larval growth, developmental delay, defective anterior spiracle eversion and lethality. Limiting the duration of toxin expression reveals differences in the critical periods for these effects. Embryonic expression causes developmental defects and partially penetrant pre-pupal lethality. Survivors of embryonic expression, however, ultimately become viable adults. In contrast, post-embryonic toxin expression results in fully penetrant lethality. To better define the larval growth defect, we used a variety of assays to demonstrate that toxin-targeted larvae are capable of locating, ingesting and clearing food and they exhibit normal food search behaviors. Strikingly, however, following food exposure these larvae show a rapid decrease in consumption suggesting a satiety-like phenomenon that correlates with the period of impaired larval growth. Together, these data suggest a critical role for these enhancer-defined lineages in regulating feeding, growth and viability.
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224
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Lewis L, Siju K, Aso Y, Friedrich A, Bulteel A, Rubin G, Grunwald Kadow I. A Higher Brain Circuit for Immediate Integration of Conflicting Sensory Information in Drosophila. Curr Biol 2015; 25:2203-14. [DOI: 10.1016/j.cub.2015.07.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 06/18/2015] [Accepted: 07/06/2015] [Indexed: 10/23/2022]
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225
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Ko KI, Root CM, Lindsay SA, Zaninovich OA, Shepherd AK, Wasserman SA, Kim SM, Wang JW. Starvation promotes concerted modulation of appetitive olfactory behavior via parallel neuromodulatory circuits. eLife 2015; 4:e08298. [PMID: 26208339 PMCID: PMC4531282 DOI: 10.7554/elife.08298] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/24/2015] [Indexed: 12/19/2022] Open
Abstract
The internal state of an organism influences its perception of attractive or aversive stimuli and thus promotes adaptive behaviors that increase its likelihood of survival. The mechanisms underlying these perceptual shifts are critical to our understanding of how neural circuits support animal cognition and behavior. Starved flies exhibit enhanced sensitivity to attractive odors and reduced sensitivity to aversive odors. Here, we show that a functional remodeling of the olfactory map is mediated by two parallel neuromodulatory systems that act in opposing directions on olfactory attraction and aversion at the level of the first synapse. Short neuropeptide F sensitizes an antennal lobe glomerulus wired for attraction, while tachykinin (DTK) suppresses activity of a glomerulus wired for aversion. Thus we show parallel neuromodulatory systems functionally reconfigure early olfactory processing to optimize detection of nutrients at the risk of ignoring potentially toxic food resources.
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Affiliation(s)
- Kang I Ko
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Cory M Root
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Scott A Lindsay
- Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Orel A Zaninovich
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Andrew K Shepherd
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Steven A Wasserman
- Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Susy M Kim
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Jing W Wang
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
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226
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Kuo SY, Wu CL, Hsieh MY, Lin CT, Wen RK, Chen LC, Chen YH, Yu YW, Wang HD, Su YJ, Lin CJ, Yang CY, Guan HY, Wang PY, Lan TH, Fu TF. PPL2ab neurons restore sexual responses in aged Drosophila males through dopamine. Nat Commun 2015; 6:7490. [PMID: 26123524 PMCID: PMC4491191 DOI: 10.1038/ncomms8490] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 05/14/2015] [Indexed: 01/08/2023] Open
Abstract
Male sexual desire typically declines with ageing. However, our understanding of the neurobiological basis for this phenomenon is limited by our knowledge of the brain circuitry and neuronal pathways controlling male sexual desire. A number of studies across species suggest that dopamine (DA) affects sexual desire. Here we use genetic tools and behavioural assays to identify a novel subset of DA neurons that regulate age-associated male courtship activity in Drosophila. We find that increasing DA levels in a subset of cells in the PPL2ab neuronal cluster is necessary and sufficient for increased sustained courtship in both young and aged male flies. Our results indicate that preventing the age-related decline in DA levels in PPL2ab neurons alleviates diminished courtship behaviours in male Drosophila. These results may provide the foundation for deciphering the circuitry involved in sexual motivation in the male Drosophila brain. We currently lack a detailed understanding of the neurobiological basis for the decline of male sexual desire with age. Here the authors demonstrate that restoring impaired dopaminergic signalling in a specific cluster of neurons in the Drosophila brain increases sexual behaviour in ageing male flies.
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Affiliation(s)
- Shu-Yun Kuo
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Chia-Lin Wu
- 1] Department of Biochemistry and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 33302 Taoyuan, Taiwan [2] Department of Medical Research, Chang Gung Memorial Hospital, 33305 Taoyuan, Taiwan
| | - Min-Yen Hsieh
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Chen-Ta Lin
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Rong-Kun Wen
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Lien-Cheng Chen
- Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, 70703 Tainan, Taiwan
| | - Yu-Hui Chen
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Yhu-Wei Yu
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Horng-Dar Wang
- Institute of Biotechnology, Institute of Systems Neuroscience, and Department of Life Science, National Tsing Hua University, 30013 Hsinchu, Taiwan
| | - Yi-Ju Su
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Chun-Ju Lin
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Cian-Yi Yang
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Hsien-Yu Guan
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
| | - Pei-Yu Wang
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, 10051 Taipei, Taiwan
| | - Tsuo-Hung Lan
- 1] Department of Psychiatry, School of Medicine, National Yang Ming University, 11221 Taipei, Taiwan [2] Department of Psychiatry, Taichung Veterans General Hospital, 40705 Taichung, Taiwan
| | - Tsai-Feng Fu
- Department of Applied Chemistry, National Chi Nan University, 54561 Nantou, Taiwan
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227
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Yamazoe-Umemoto A, Fujita K, Iino Y, Iwasaki Y, Kimura KD. Modulation of different behavioral components by neuropeptide and dopamine signalings in non-associative odor learning of Caenorhabditis elegans. Neurosci Res 2015; 99:22-33. [PMID: 26068898 DOI: 10.1016/j.neures.2015.05.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 05/15/2015] [Accepted: 05/18/2015] [Indexed: 12/20/2022]
Abstract
An animal's behavior is modulated by learning; however, the behavioral component modulated by learning and the mechanisms of this modulation have not been fully understood. We show here that two types of neural signalings are required for the modulation of different behavioral components in non-associative odor learning in the nematode Caenorhabditis elegans. We have previously found that C. elegans avoid the repulsive odor 2-nonanone, and preexposure to the odor for 1h enhances the avoidance behavior as a type of non-associative learning. Systematic quantitative analyses of behavioral components revealed that the odor preexposure caused increases in average duration of straight migration ("runs") only when the animals were migrating away from the odor source within a certain range of bearing, which likely corresponds to odor decrement. Further, genetic analyses revealed that the genes for neuropeptide or dopamine signalings are both required for the enhanced odor avoidance. Neuropeptide signaling genes were required for the preexposure-dependent increase in run duration. In contrast, dopamine signaling genes were required not for the increase in run duration but likely for maintenance of run direction. Our results suggests that multiple behavioral components are regulated by different neuromodulators even in non-associative learning in C. elegans.
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Affiliation(s)
- Akiko Yamazoe-Umemoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Kosuke Fujita
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuichi Iino
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuishi Iwasaki
- Department of Intelligent System Engineering, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| | - Koutarou D Kimura
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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228
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Gibson WT, Gonzalez CR, Fernandez C, Ramasamy L, Tabachnik T, Du RR, Felsen PD, Maire MR, Perona P, Anderson DJ. Behavioral responses to a repetitive visual threat stimulus express a persistent state of defensive arousal in Drosophila. Curr Biol 2015; 25:1401-15. [PMID: 25981791 DOI: 10.1016/j.cub.2015.03.058] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/03/2015] [Accepted: 03/30/2015] [Indexed: 12/25/2022]
Abstract
The neural circuit mechanisms underlying emotion states remain poorly understood. Drosophila offers powerful genetic approaches for dissecting neural circuit function, but whether flies exhibit emotion-like behaviors has not been clear. We recently proposed that model organisms may express internal states displaying "emotion primitives," which are general characteristics common to different emotions, rather than specific anthropomorphic emotions such as "fear" or "anxiety." These emotion primitives include scalability, persistence, valence, and generalization to multiple contexts. Here, we have applied this approach to determine whether flies' defensive responses to moving overhead translational stimuli ("shadows") are purely reflexive or may express underlying emotion states. We describe a new behavioral assay in which flies confined in an enclosed arena are repeatedly exposed to an overhead translational stimulus. Repetitive stimuli promoted graded (scalable) and persistent increases in locomotor velocity and hopping, and occasional freezing. The stimulus also dispersed feeding flies from a food resource, suggesting both negative valence and context generalization. Strikingly, there was a significant delay before the flies returned to the food following stimulus-induced dispersal, suggestive of a slowly decaying internal defensive state. The length of this delay was increased when more stimuli were delivered for initial dispersal. These responses can be mathematically modeled by assuming an internal state that behaves as a leaky integrator of stimulus exposure. Our results suggest that flies' responses to repetitive visual threat stimuli express an internal state exhibiting canonical emotion primitives, possibly analogous to fear in mammals. The mechanistic basis of this state can now be investigated in a genetically tractable insect species.
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Affiliation(s)
- William T Gibson
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA; Division of Biology & Biological Engineering 156-29, California Institute of Technology, Pasadena, CA 91125, USA; Division of Engineering & Applied Sciences 136-93, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Carlos R Gonzalez
- Division of Engineering & Applied Sciences 136-93, California Institute of Technology, Pasadena, CA 91125, USA
| | - Conchi Fernandez
- Division of Engineering & Applied Sciences 136-93, California Institute of Technology, Pasadena, CA 91125, USA
| | - Lakshminarayanan Ramasamy
- Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Tanya Tabachnik
- Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Rebecca R Du
- Division of Biology & Biological Engineering 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | - Panna D Felsen
- Division of Engineering & Applied Sciences 136-93, California Institute of Technology, Pasadena, CA 91125, USA
| | - Michael R Maire
- Division of Engineering & Applied Sciences 136-93, California Institute of Technology, Pasadena, CA 91125, USA
| | - Pietro Perona
- Division of Engineering & Applied Sciences 136-93, California Institute of Technology, Pasadena, CA 91125, USA
| | - David J Anderson
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA; Division of Biology & Biological Engineering 156-29, California Institute of Technology, Pasadena, CA 91125, USA; Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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229
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Alekseyenko OV, Kravitz EA. Serotonin and the search for the anatomical substrate of aggression. Fly (Austin) 2015; 8:200-5. [PMID: 25923771 DOI: 10.1080/19336934.2015.1045171] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
All species of animals display aggression in order to obtain resources such as territories, mates, or food. Appropriate displays of aggression rely on the correct identification of a potential competitor, an evaluation of the environmental signals, and the physiological state of the animal. With a hard-wired circuitry involving fixed numbers of neurons, neuromodulators like serotonin offer adaptive flexibility in behavioral responses without changing the "hard-wiring". In a recent report, we combined intersectional genetics, quantitative behavioral assays and morphological analyses to identify single serotonergic neurons that modulate the escalation of aggression. We found anatomical target areas within the brain where these neurons appear to form synaptic contacts with 5HT1A receptor-expressing neurons, and then confirmed the likelihood of those connections on a functional level. In this Extra View article, we offer an extended discussion of these recent findings and elaborate on how they can link a cellular and functional mapping of an aggression-regulating circuit at a single-cell resolution level.
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230
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Abstract
The involvement of associative learning cues has been demonstrated in several stages of feeding and food selection. Short neuropeptide F (sNPF), an insect neuropeptide whose effects on feeding behavior have previously been well established, may be one of the factors bridging feeding and learning behavior. Recently, it was shown in Drosophila melanogaster that the targeted reduction of Drome-sNPF transcript levels significantly reduced sugar-rewarded olfactory memory. While Drosophila mainly relies on olfactory perception in its food searching behavior, locust foraging behavior is likely to be more visually orientated. Furthermore, a feeding-dependent regulation of Schgr-sNPF transcript levels has previously been observed in the optic lobes of the locust brain, suggesting a possible involvement in visual perception of food and visual associative memory in this insect species. In this study, we describe the development of a robust and reproducible assay allowing visual associative memory to be studied in the desert locust, Schistocerca gregaria. Furthermore, we performed an exploratory series of experiments, studying the role of Schgr-sNPF in this complex process.
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231
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Dietrich MO, Zimmer MR, Bober J, Horvath TL. Hypothalamic Agrp neurons drive stereotypic behaviors beyond feeding. Cell 2015; 160:1222-32. [PMID: 25748653 PMCID: PMC4484787 DOI: 10.1016/j.cell.2015.02.024] [Citation(s) in RCA: 183] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/16/2015] [Accepted: 01/30/2015] [Indexed: 02/07/2023]
Abstract
The nervous system evolved to coordinate flexible goal-directed behaviors by integrating interoceptive and sensory information. Hypothalamic Agrp neurons are known to be crucial for feeding behavior. Here, however, we show that these neurons also orchestrate other complex behaviors in adult mice. Activation of Agrp neurons in the absence of food triggers foraging and repetitive behaviors, which are reverted by food consumption. These stereotypic behaviors that are triggered by Agrp neurons are coupled with decreased anxiety. NPY5 receptor signaling is necessary to mediate the repetitive behaviors after Agrp neuron activation while having minor effects on feeding. Thus, we have unmasked a functional role for Agrp neurons in controlling repetitive behaviors mediated, at least in part, by neuropeptidergic signaling. The findings reveal a new set of behaviors coupled to the energy homeostasis circuit and suggest potential therapeutic avenues for diseases with stereotypic behaviors.
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Affiliation(s)
- Marcelo O Dietrich
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Graduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035, Brazil.
| | - Marcelo R Zimmer
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Graduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035, Brazil
| | - Jeremy Bober
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Kavli Institute for Neuroscience at Yale University, New Haven, CT 06520, USA
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232
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Kain P, Dahanukar A. Secondary taste neurons that convey sweet taste and starvation in the Drosophila brain. Neuron 2015; 85:819-32. [PMID: 25661186 DOI: 10.1016/j.neuron.2015.01.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/29/2014] [Accepted: 01/08/2015] [Indexed: 11/16/2022]
Abstract
The gustatory system provides vital sensory information to determine feeding and appetitive learning behaviors. Very little is known, however, about higher-order gustatory circuits in the highly tractable model for neurobiology, Drosophila melanogaster. Here we report second-order sweet gustatory projection neurons (sGPNs) in the Drosophila brain using a powerful behavioral screen. Silencing neuronal activity reduces appetitive behaviors, whereas inducible activation results in food acceptance via proboscis extensions. sGPNs show functional connectivity with Gr5a(+) sweet taste neurons and are activated upon sucrose application to the labellum. By tracing sGPN axons, we identify the antennal mechanosensory and motor center (AMMC) as an immediate higher-order processing center for sweet taste. Interestingly, starvation increases sucrose sensitivity of the sGPNs in the AMMC, suggesting that hunger modulates the responsiveness of the secondary sweet taste relay. Together, our results provide a foundation for studying gustatory processing and its modulation by the internal nutrient state.
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Affiliation(s)
- Pinky Kain
- Department of Entomology, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Anupama Dahanukar
- Department of Entomology, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521, USA.
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233
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Musso PY, Tchenio P, Preat T. Delayed Dopamine Signaling of Energy Level Builds Appetitive Long-Term Memory in Drosophila. Cell Rep 2015; 10:1023-31. [DOI: 10.1016/j.celrep.2015.01.036] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/18/2014] [Accepted: 01/14/2015] [Indexed: 01/18/2023] Open
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234
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Haynes PR, Christmann BL, Griffith LC. A single pair of neurons links sleep to memory consolidation in Drosophila melanogaster. eLife 2015; 4:e03868. [PMID: 25564731 PMCID: PMC4305081 DOI: 10.7554/elife.03868] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 01/07/2015] [Indexed: 12/17/2022] Open
Abstract
Sleep promotes memory consolidation in humans and many other species, but the physiological and anatomical relationships between sleep and memory remain unclear. Here, we show the dorsal paired medial (DPM) neurons, which are required for memory consolidation in Drosophila, are sleep-promoting inhibitory neurons. DPMs increase sleep via release of GABA onto wake-promoting mushroom body (MB) α'/β' neurons. Functional imaging demonstrates that DPM activation evokes robust increases in chloride in MB neurons, but is unable to cause detectable increases in calcium or cAMP. Downregulation of α'/β' GABAA and GABABR3 receptors results in sleep loss, suggesting these receptors are the sleep-relevant targets of DPM-mediated inhibition. Regulation of sleep by neurons necessary for consolidation suggests that these brain processes may be functionally interrelated via their shared anatomy. These findings have important implications for the mechanistic relationship between sleep and memory consolidation, arguing for a significant role of inhibitory neurotransmission in regulating these processes.
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Affiliation(s)
- Paula R Haynes
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
| | - Bethany L Christmann
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
| | - Leslie C Griffith
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
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235
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Aso Y, Sitaraman D, Ichinose T, Kaun KR, Vogt K, Belliart-Guérin G, Plaçais PY, Robie AA, Yamagata N, Schnaitmann C, Rowell WJ, Johnston RM, Ngo TTB, Chen N, Korff W, Nitabach MN, Heberlein U, Preat T, Branson KM, Tanimoto H, Rubin GM. Mushroom body output neurons encode valence and guide memory-based action selection in Drosophila. eLife 2014; 3:e04580. [PMID: 25535794 PMCID: PMC4273436 DOI: 10.7554/elife.04580] [Citation(s) in RCA: 419] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 11/07/2014] [Indexed: 12/11/2022] Open
Abstract
Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by ∼2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types. We studied the role of MBONs in several associative learning tasks and in sleep regulation, revealing the extent to which information flow is segregated into distinct channels and suggesting possible roles for the multi-layered MBON network. We also show that optogenetic activation of MBONs can, depending on cell type, induce repulsion or attraction in flies. The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence. We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli. Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection.
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Affiliation(s)
- Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Divya Sitaraman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, United States
- Department of Genetics, Yale School of Medicine, New Haven, United States
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, New Haven, United States
| | - Toshiharu Ichinose
- Max Planck Institute of Neurobiology, Martinsried, Germany
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Karla R Kaun
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Katrin Vogt
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Ghislain Belliart-Guérin
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, Centre National de la Recherche Scientifique, ESPCI, Paris, France
| | - Pierre-Yves Plaçais
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, Centre National de la Recherche Scientifique, ESPCI, Paris, France
| | - Alice A Robie
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Nobuhiro Yamagata
- Max Planck Institute of Neurobiology, Martinsried, Germany
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | | | - William J Rowell
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Rebecca M Johnston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Teri-T B Ngo
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Nan Chen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Wyatt Korff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Michael N Nitabach
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, United States
- Department of Genetics, Yale School of Medicine, New Haven, United States
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, New Haven, United States
| | - Ulrike Heberlein
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Thomas Preat
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, Centre National de la Recherche Scientifique, ESPCI, Paris, France
| | - Kristin M Branson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Hiromu Tanimoto
- Max Planck Institute of Neurobiology, Martinsried, Germany
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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236
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Aso Y, Hattori D, Yu Y, Johnston RM, Iyer NA, Ngo TTB, Dionne H, Abbott LF, Axel R, Tanimoto H, Rubin GM. The neuronal architecture of the mushroom body provides a logic for associative learning. eLife 2014; 3:e04577. [PMID: 25535793 PMCID: PMC4273437 DOI: 10.7554/elife.04577] [Citation(s) in RCA: 605] [Impact Index Per Article: 60.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 11/05/2014] [Indexed: 12/18/2022] Open
Abstract
We identified the neurons comprising the Drosophila mushroom body (MB), an associative center in invertebrate brains, and provide a comprehensive map describing their potential connections. Each of the 21 MB output neuron (MBON) types elaborates segregated dendritic arbors along the parallel axons of ∼2000 Kenyon cells, forming 15 compartments that collectively tile the MB lobes. MBON axons project to five discrete neuropils outside of the MB and three MBON types form a feedforward network in the lobes. Each of the 20 dopaminergic neuron (DAN) types projects axons to one, or at most two, of the MBON compartments. Convergence of DAN axons on compartmentalized Kenyon cell-MBON synapses creates a highly ordered unit that can support learning to impose valence on sensory representations. The elucidation of the complement of neurons of the MB provides a comprehensive anatomical substrate from which one can infer a functional logic of associative olfactory learning and memory.
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Affiliation(s)
- Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Daisuke Hattori
- Howard Hughes Medical Institute, Columbia University, New York, United States
| | - Yang Yu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Rebecca M Johnston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Nirmala A Iyer
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Teri-T B Ngo
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Heather Dionne
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - L F Abbott
- Department of Neuroscience, College of Physicians and Surgeons, Columbia University, New York, United States
| | - Richard Axel
- Howard Hughes Medical Institute, Columbia University, New York, United States
| | - Hiromu Tanimoto
- Tohuku University Graduate School of Life Sciences, Sendai, Japan
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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237
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Reisenman CE. Hunger is the best spice: effects of starvation in the antennal responses of the blood-sucking bug Rhodnius prolixus. JOURNAL OF INSECT PHYSIOLOGY 2014; 71:8-13. [PMID: 25280630 PMCID: PMC4258481 DOI: 10.1016/j.jinsphys.2014.09.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/18/2014] [Accepted: 09/22/2014] [Indexed: 06/03/2023]
Abstract
Blood-sucking insects strongly rely on olfactory cues to find their vertebrate hosts. As in other insects with different lifestyles, it has been shown that endogenous and exogenous factors modulate olfactory responses. The triatomine bug Rhodnius prolixus is an important vector of Chagas disease and a classical model for studies of physiology and behavior. In this species, the behavioral response to host-derived odorants is modulated by both the time of the day and the starvation. Here I investigated the peripheral neural mechanisms underlying these modulatory effects. For this, I measured the electroantennogram (EAG) responses of insects towards different concentrations (from 0.5% to 75% vol/vol) of an attractive host-odorant, ammonia. I tested the responses of starved and fed animals during the middle of the day (when insects are inactive and aggregated in refuges) and at the beginning of the night (when insects become active and search for hosts). Regardless of the time of the day and the starvation status, EAG responses systematically increased with odorant concentration, thus accurately reflecting the response of olfactory receptor cells. Interestingly, the EAG responses of starved insects were larger than those of fed insects only during the night, with larger differences (6-7 times) observed at low-middle concentrations. This study is the first reporting modulation of sensory responses at the neural level in triatomines. This modulation, considering that triatomine hosts are mostly diurnal and are also potential predators, has an important adaptive value, ensuring that insects search for hosts only when they are hungry and at appropriate times.
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Affiliation(s)
- Carolina E Reisenman
- Department of Molecular and Cell Biology, University of California, Berkeley, 16 Barker Hall # 3204, Berkeley, CA 94720-3204, United States.
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238
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Lin S, Owald D, Chandra V, Talbot C, Huetteroth W, Waddell S. Neural correlates of water reward in thirsty Drosophila. Nat Neurosci 2014; 17:1536-42. [PMID: 25262493 PMCID: PMC4213141 DOI: 10.1038/nn.3827] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/01/2014] [Indexed: 11/09/2022]
Abstract
Drinking water is innately rewarding to thirsty animals. In addition, the consumed value can be assigned to behavioral actions and predictive sensory cues by associative learning. Here we show that thirst converts water avoidance into water-seeking in naive Drosophila melanogaster. Thirst also permitted flies to learn olfactory cues paired with water reward. Water learning required water taste and <40 water-responsive dopaminergic neurons that innervate a restricted zone of the mushroom body γ lobe. These water learning neurons are different from those that are critical for conveying the reinforcing effects of sugar. Naive water-seeking behavior in thirsty flies did not require water taste but relied on another subset of water-responsive dopaminergic neurons that target the mushroom body β' lobe. Furthermore, these naive water-approach neurons were not required for learned water-seeking. Our results therefore demonstrate that naive water-seeking, learned water-seeking and water learning use separable neural circuitry in the brain of thirsty flies.
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Affiliation(s)
- Suewei Lin
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - David Owald
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - Vikram Chandra
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
- Balliol College, The University of Oxford, Broad Street, Oxford, OX1 3BJ, UK
| | - Clifford Talbot
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - Wolf Huetteroth
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, UK
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239
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Alekseyenko OV, Chan YB, Fernandez MDLP, Bülow T, Pankratz MJ, Kravitz EA. Single serotonergic neurons that modulate aggression in Drosophila. Curr Biol 2014; 24:2700-7. [PMID: 25447998 DOI: 10.1016/j.cub.2014.09.051] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/18/2014] [Accepted: 09/19/2014] [Indexed: 12/23/2022]
Abstract
Monoamine serotonin (5HT) has been linked to aggression for many years across species. However, elaboration of the neurochemical pathways that govern aggression has proven difficult because monoaminergic neurons also regulate other behaviors. There are approximately 100 serotonergic neurons in the Drosophila nervous system, and they influence sleep, circadian rhythms, memory, and courtship. In the Drosophila model of aggression, the acute shut down of the entire serotonergic system yields flies that fight less, whereas induced activation of 5HT neurons promotes aggression. Using intersectional genetics, we restricted the population of 5HT neurons that can be reproducibly manipulated to identify those that modulate aggression. Although similar approaches were used recently to find aggression-modulating dopaminergic and Fru(M)-positive peptidergic neurons, the downstream anatomical targets of the neurons that make up aggression-controlling circuits remain poorly understood. Here, we identified a symmetrical pair of serotonergic PLP neurons that are necessary for the proper escalation of aggression. Silencing these neurons reduced aggression in male flies, and activating them increased aggression in male flies. GFP reconstitution across synaptic partners (GRASP) analyses suggest that 5HT-PLP neurons form contacts with 5HT1A receptor-expressing neurons in two distinct anatomical regions of the brain. Activation of these 5HT1A receptor-expressing neurons, in turn, caused reductions in aggression. Our studies, therefore, suggest that aggression may be held in check, at least in part, by inhibitory input from 5HT1A receptor-bearing neurons, which can be released by activation of the 5HT-PLP neurons.
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Affiliation(s)
- Olga V Alekseyenko
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Yick-Bun Chan
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Maria de la Paz Fernandez
- Instituto de Investigación en Biomedicina de Buenos Aires - CONICET - Partner Institute of the Max Planck Society, Buenos Aires C1425FQD, Argentina
| | - Torsten Bülow
- Molecular Brain Physiology and Behavior, LIMES Institute, University of Bonn, Bonn 53115, Germany
| | - Michael J Pankratz
- Molecular Brain Physiology and Behavior, LIMES Institute, University of Bonn, Bonn 53115, Germany
| | - Edward A Kravitz
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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240
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Independent, reciprocal neuromodulatory control of sweet and bitter taste sensitivity during starvation in Drosophila. Neuron 2014; 84:806-20. [PMID: 25451195 DOI: 10.1016/j.neuron.2014.09.032] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2014] [Indexed: 11/22/2022]
Abstract
An organism's behavioral decisions often depend upon the relative strength of appetitive and aversive sensory stimuli, the relative sensitivity to which can be modified by internal states like hunger. However, whether sensitivity to such opposing influences is modulated in a unidirectional or bidirectional manner is not clear. Starved flies exhibit increased sugar and decreased bitter sensitivity. It is widely believed that only sugar sensitivity changes, and that this masks bitter sensitivity. Here we use gene- and circuit-level manipulations to show that sweet and bitter sensitivity are independently and reciprocally regulated by starvation in Drosophila. We identify orthogonal neuromodulatory cascades that oppositely control peripheral taste sensitivity for each modality. Moreover, these pathways are recruited at increasing hunger levels, such that low-risk changes (higher sugar sensitivity) precede high-risk changes (lower sensitivity to potentially toxic resources). In this way, state-intensity-dependent, reciprocal regulation of appetitive and aversive peripheral gustatory sensitivity permits flexible, adaptive feeding decisions.
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241
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Affiliation(s)
| | - Josh Dubnau
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
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242
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Padmanabha D, Baker KD. Drosophila gains traction as a repurposed tool to investigate metabolism. Trends Endocrinol Metab 2014; 25:518-27. [PMID: 24768030 DOI: 10.1016/j.tem.2014.03.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/20/2014] [Accepted: 03/25/2014] [Indexed: 10/25/2022]
Abstract
The use of fruit flies has recently emerged as a powerful experimental paradigm to study the core aspects of energy metabolism. The fundamental need for lipid and carbohydrate processing and storage across species dictates that the central regulators that control metabolism are highly conserved through evolution. Accordingly, the Drosophila system is being used to identify human disease genes and has the potential to model successfully human disorders that center on excessive caloric intake and metabolic dysfunction, including diet-induced lipotoxicity and type 2 diabetes. We review here recent progress on this front and contend that increasing such efforts will yield unexpectedly high rates of experimental return, thereby leading to novel approaches in the treatment of obesity and its comorbidities.
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Affiliation(s)
- Divya Padmanabha
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, 1220 East Broad Street Room 2052, Richmond, VA 23298, USA
| | - Keith D Baker
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, 1220 East Broad Street Room 2052, Richmond, VA 23298, USA.
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243
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Simcock NK, Gray HE, Wright GA. Single amino acids in sucrose rewards modulate feeding and associative learning in the honeybee. JOURNAL OF INSECT PHYSIOLOGY 2014; 69:41-8. [PMID: 24819203 PMCID: PMC4194351 DOI: 10.1016/j.jinsphys.2014.05.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 04/23/2014] [Accepted: 05/01/2014] [Indexed: 05/08/2023]
Abstract
Obtaining the correct balance of nutrients requires that the brain integrates information about the body's nutritional state with sensory information from food to guide feeding behaviour. Learning is a mechanism that allows animals to identify cues associated with nutrients so that they can be located quickly when required. Feedback about nutritional state is essential for nutrient balancing and could influence learning. How specific this feedback is to individual nutrients has not often been examined. Here, we tested how the honeybee's nutritional state influenced the likelihood it would feed on and learn sucrose solutions containing single amino acids. Nutritional state was manipulated by pre-feeding bees with either 1M sucrose or 1M sucrose containing 100mM of isoleucine, proline, phenylalanine, or methionine 24h prior to olfactory conditioning of the proboscis extension response. We found that bees pre-fed sucrose solution consumed less of solutions containing amino acids and were also less likely to learn to associate amino acid solutions with odours. Unexpectedly, bees pre-fed solutions containing an amino acid were also less likely to learn to associate odours with sucrose the next day. Furthermore, they consumed more of and were more likely to learn when rewarded with an amino acid solution if they were pre-fed isoleucine and proline. Our data indicate that single amino acids at relatively high concentrations inhibit feeding on sucrose solutions containing them, and they can act as appetitive reinforcers during learning. Our data also suggest that select amino acids interact with mechanisms that signal nutritional sufficiency to reduce hunger. Based on these experiments, we predict that nutrient balancing for essential amino acids during learning requires integration of information about several amino acids experienced simultaneously.
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Affiliation(s)
- Nicola K Simcock
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Helen E Gray
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Geraldine A Wright
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
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244
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Haverkamp A, Smid HM. Octopamine-like immunoreactive neurons in the brain and subesophageal ganglion of the parasitic wasps Nasonia vitripennis and N. giraulti. Cell Tissue Res 2014; 358:313-29. [PMID: 25107606 DOI: 10.1007/s00441-014-1960-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 07/03/2014] [Indexed: 10/24/2022]
Abstract
Octopamine is an important neuromodulator in the insect nervous system, influencing memory formation, sensory perception and motor control. In this study, we compare the distribution of octopamine-like immunoreactive neurons in two parasitic wasp species of the Nasonia genus, N. vitripennis and N. giraulti. These two species were previously described as differing in their learning and memory formation, which raised the question as to whether morphological differences in octopaminergic neurons underpinned these variations. Immunohistochemistry in combination with confocal laser scanning microscopy was used to reveal and compare the somata and major projections of the octopaminergic neurons in these wasps. The brains of both species showed similar staining patterns, with six different neuron clusters being identified in the brain and five different clusters in the subesophageal ganglion. Of those clusters found in the subesophageal ganglion, three contained unpaired neurons, whereas the other three consisted in paired neurons. The overall pattern of octopaminergic neurons in both species was similar, with no differences in the numbers or projections of the ventral unpaired median (VUM) neurons, which are known to be involved in memory formation in insects. In one other cluster in the brain, located in-between the optic lobe and the antennal lobe, we detected more neurons in N. vitripennis compared with N. giraulti. Combining our results with findings made previously in other Hymenopteran species, we discuss possible functions and some of the ultimate factors influencing the evolution of the octopaminergic system in the insect brain.
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Affiliation(s)
- Alexander Haverkamp
- Laboratory of Entomology, Wageningen University, PO Box 8031, 6700 EH, Wageningen, The Netherlands
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245
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Das G, Klappenbach M, Vrontou E, Perisse E, Clark CM, Burke CJ, Waddell S. Drosophila learn opposing components of a compound food stimulus. Curr Biol 2014; 24:1723-30. [PMID: 25042590 PMCID: PMC4131107 DOI: 10.1016/j.cub.2014.05.078] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 04/28/2014] [Accepted: 05/21/2014] [Indexed: 11/29/2022]
Abstract
Dopaminergic neurons provide value signals in mammals and insects. During Drosophila olfactory learning, distinct subsets of dopaminergic neurons appear to assign either positive or negative value to odor representations in mushroom body neurons. However, it is not known how flies evaluate substances that have mixed valence. Here we show that flies form short-lived aversive olfactory memories when trained with odors and sugars that are contaminated with the common insect repellent DEET. This DEET-aversive learning required the MB-MP1 dopaminergic neurons that are also required for shock learning. Moreover, differential conditioning with DEET versus shock suggests that formation of these distinct aversive olfactory memories relies on a common negatively reinforcing dopaminergic mechanism. Surprisingly, as time passed after training, the behavior of DEET-sugar-trained flies reversed from conditioned odor avoidance into odor approach. In addition, flies that were compromised for reward learning exhibited a more robust and longer-lived aversive-DEET memory. These data demonstrate that flies independently process the DEET and sugar components to form parallel aversive and appetitive olfactory memories, with distinct kinetics, that compete to guide learned behavior.
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Affiliation(s)
- Gaurav Das
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Martín Klappenbach
- Laboratorio de Neurobiología de la Memoria, Facultad de Ciencias Exactas y Naturales, IFIBYNE-CONICET, Universidad de Buenos Aires, Buenos Aires C1428EGA, Argentina
| | - Eleftheria Vrontou
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Emmanuel Perisse
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Christopher M Clark
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Christopher J Burke
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK; Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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246
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Feeding regulation in Drosophila. Curr Opin Neurobiol 2014; 29:57-63. [PMID: 24937262 DOI: 10.1016/j.conb.2014.05.008] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 05/17/2014] [Accepted: 05/22/2014] [Indexed: 11/22/2022]
Abstract
Neuromodulators play a key role in adjusting animal behavior based on environmental cues and internal needs. Here, we review the regulation of Drosophila feeding behavior to illustrate how neuromodulators achieve behavioral plasticity. Recent studies have made rapid progress in determining molecular and cellular mechanisms that translate the metabolic needs of the fly into changes in neuroendocrine and neuromodulatory states. These neuromodulators in turn promote or inhibit discrete feeding behavioral subprograms. This review highlights the links between physiological needs, neuromodulatory states, and feeding decisions.
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247
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Heisenberg M. The Beauty of the Network in the Brain and the Origin of the Mind in the Control of Behavior. J Neurogenet 2014; 28:389-99. [DOI: 10.3109/01677063.2014.912279] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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248
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Su CY, Wang JW. Modulation of neural circuits: how stimulus context shapes innate behavior in Drosophila. Curr Opin Neurobiol 2014; 29:9-16. [PMID: 24801064 DOI: 10.1016/j.conb.2014.04.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 04/03/2014] [Accepted: 04/10/2014] [Indexed: 11/25/2022]
Abstract
Remarkable advances have been made in recent years in our understanding of innate behavior and the underlying neural circuits. In particular, a wealth of neuromodulatory mechanisms have been uncovered that can alter the input-output relationship of a hereditary neural circuit. It is now clear that this inbuilt flexibility allows animals to modify their behavioral responses according to environmental cues, metabolic demands and physiological states. Here, we discuss recent insights into how modulation of neural circuits impacts innate behavior, with a special focus on how environmental cues and internal physiological states shape different aspects of feeding behavior in Drosophila.
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Affiliation(s)
- Chih-Ying Su
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, United States
| | - Jing W Wang
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, United States.
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249
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Abstract
It is now almost forty years since the first description of learning in the fruit fly Drosophila melanogaster. Various incarnations of the classic mutagenesis approach envisaged in the early days have provided around one hundred learning defective mutant fly strains. Recent technological advances permit temporal control of neural function in the behaving fly. These approaches have radically changed experiments in the field and have provided a neural circuit perspective of memory formation, consolidation and retrieval. Combining neural perturbations with more classical mutant intervention allows investigators to interrogate the molecular and cellular processes of memory within the defined neural circuits. Here, we summarize some of the progress made in the last ten years that indicates a remarkable conservation of the neural mechanisms of memory formation between flies and mammals. We emphasize that considering an ethologically-relevant viewpoint might provide additional experimental power in studies of Drosophila memory.
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250
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Bjordal M, Arquier N, Kniazeff J, Pin JP, Léopold P. Sensing of amino acids in a dopaminergic circuitry promotes rejection of an incomplete diet in Drosophila. Cell 2014; 156:510-21. [PMID: 24485457 DOI: 10.1016/j.cell.2013.12.024] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/07/2013] [Accepted: 11/15/2013] [Indexed: 01/18/2023]
Abstract
The brain is the central organizer of food intake, matching the quality and quantity of the food sources with organismal needs. To ensure appropriate amino acid balance, many species reject a diet lacking one or several essential amino acids (EAAs) and seek out a better food source. Here, we show that, in Drosophila larvae, this behavior relies on innate sensing of amino acids in dopaminergic (DA) neurons of the brain. We demonstrate that the amino acid sensor GCN2 acts upstream of GABA signaling in DA neurons to promote avoidance of the EAA-deficient diet. Using real-time calcium imaging in larval brains, we show that amino acid imbalance induces a rapid and reversible activation of three DA neurons that are necessary and sufficient for food rejection. Taken together, these data identify a central amino-acid-sensing mechanism operating in specific DA neurons and controlling food intake.
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Affiliation(s)
- Marianne Bjordal
- University of Nice-Sophia Antipolis, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; CNRS, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; INSERM, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France
| | - Nathalie Arquier
- University of Nice-Sophia Antipolis, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; CNRS, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; INSERM, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France
| | - Julie Kniazeff
- Institut de Génomique Fonctionnelle, CNRS UMR5203, INSERM U661, Université Montpellier 1 & 2, 34094 Montpellier, France
| | - Jean Philippe Pin
- Institut de Génomique Fonctionnelle, CNRS UMR5203, INSERM U661, Université Montpellier 1 & 2, 34094 Montpellier, France
| | - Pierre Léopold
- University of Nice-Sophia Antipolis, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; CNRS, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; INSERM, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France.
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