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Helfrich-Förster C. The Never Given 2022 Pittendrigh/Aschoff Lecture: The Clock Network in the Brain-Insights From Insects. J Biol Rhythms 2025; 40:120-142. [PMID: 39529231 PMCID: PMC11915775 DOI: 10.1177/07487304241290861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2024]
Abstract
My journey into chronobiology began in 1977 with lectures and internships with Wolfgang Engelmann and Hans Erkert at the University of Tübingen in Germany. At that time, the only known animal clock gene was Period, and the location and organization of the master circadian clock in the brain was completely unknown for the model insect Drosophila melanogaster. I was thus privileged to witness and participate in the research that led us from discovering the first clock gene to identifying the clock network in the fly brain and the putative pathways linking it to behavior and physiology. This article highlights my role in these developments and also shows how the successful use of D. melanogaster for studies of circadian rhythms has contributed to the understanding of clock networks in other animals. I also report on my experiences in the German scientific system and hope that my story will be of interest to some of you.
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Affiliation(s)
- Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
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2
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Roy T, Beer K. Time memory in social insects with a special focus on honey bees. CURRENT OPINION IN INSECT SCIENCE 2025; 68:101327. [PMID: 39675629 DOI: 10.1016/j.cois.2024.101327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 11/25/2024] [Accepted: 12/10/2024] [Indexed: 12/17/2024]
Abstract
The ability to associate time and location with food sources is an evolutionary advantage for foraging animals. We find highly sophisticated time memory capabilities especially in social insects, which require efficient foraging capabilities for colony provisioning. Honey bees are perfectly suitable to study time memory mechanisms: they possess an elaborated time memory combined with a relatively simple neuronal clock network and a smaller gene set compared with the mouse model organism. This review provides a short overview majorly across insects, which have demonstrated time memory capabilities, with a focus on time-place learning, and describes basic properties as well as state-of-the-art research connecting time memory with the circadian clock at the behavioral, molecular, and neuroanatomical levels. Despite a long history of research on time memory of honey bees, putative connections between clock and time memory have only recently been identified and imply a rather complex regulation mechanism with multiple signaling pathways.
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Affiliation(s)
- Tiyasa Roy
- National Centre for Biological Sciences - Tata Institute of Fundamental Research, Bengaluru, Karnataka, India
| | - Katharina Beer
- Behavioral Physiology & Sociobiology, Biocentre, University of Würzburg, Würzburg, Germany.
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3
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Ehrlich A, Xu AA, Luminari S, Kidd S, Treiber CD, Russo J, Blau J. Tango-seq: overlaying transcriptomics on connectomics to identify neurons downstream of Drosophila clock neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.22.595372. [PMID: 38826334 PMCID: PMC11142192 DOI: 10.1101/2024.05.22.595372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Knowing how neural circuits change with neuronal plasticity and differ between individuals is important to fully understand behavior. Connectomes are typically assembled using electron microscopy, but this is low throughput and impractical for analyzing plasticity or mutations. Here, we modified the trans-Tango genetic circuit-tracing technique to identify neurons synaptically downstream of Drosophila s-LNv clock neurons, which show 24hr plasticity rhythms. s-LNv target neurons were labeled specifically in adult flies using a nuclear reporter gene, which facilitated their purification and then single cell sequencing. We call this Tango-seq, and it allows transcriptomic data - and thus cell identity - to be overlayed on top of anatomical data. We found that s-LNvs preferentially make synaptic connections with a subset of the CNMa+ DN1p clock neurons, and that these are likely plastic connections. We also identified synaptic connections between s-LNvs and mushroom body Kenyon cells. Tango-seq should be a useful addition to the connectomics toolkit.
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Affiliation(s)
- Alison Ehrlich
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Angelina A Xu
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Sofia Luminari
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Simon Kidd
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Christoph D Treiber
- Centre for Neural Circuits and Behaviour, University of Oxford, UK
- Current address: Department of Biology, University of Oxford, UK
| | - Jordan Russo
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Justin Blau
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
- Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, Abu Dhabi, UAE
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4
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Majcin Dorcikova M, Duret LC, Pottié E, Nagoshi E. Circadian clock disruption promotes the degeneration of dopaminergic neurons in male Drosophila. Nat Commun 2023; 14:5908. [PMID: 37737209 PMCID: PMC10516932 DOI: 10.1038/s41467-023-41540-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 09/08/2023] [Indexed: 09/23/2023] Open
Abstract
Sleep and circadian rhythm disruptions are frequent comorbidities of Parkinson's disease (PD), a disorder characterized by the progressive loss of dopaminergic (DA) neurons in the substantia nigra. However, the causal role of circadian clocks in the degenerative process remains uncertain. We demonstrated here that circadian clocks regulate the rhythmicity and magnitude of the vulnerability of DA neurons to oxidative stress in male Drosophila. Circadian pacemaker neurons are presynaptic to a subset of DA neurons and rhythmically modulate their susceptibility to degeneration. The arrhythmic period (per) gene null mutation exacerbates the age-dependent loss of DA neurons and, in combination with brief oxidative stress, causes premature animal death. These findings suggest that circadian clock disruption promotes dopaminergic neurodegeneration.
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Affiliation(s)
- Michaëla Majcin Dorcikova
- Department of Genetics and Evolution and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, CH-1211, Geneva, Switzerland
| | - Lou C Duret
- Department of Genetics and Evolution and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, CH-1211, Geneva, Switzerland
| | - Emma Pottié
- Department of Genetics and Evolution and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, CH-1211, Geneva, Switzerland
| | - Emi Nagoshi
- Department of Genetics and Evolution and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, CH-1211, Geneva, Switzerland.
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5
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Gonulkirmaz-Cancalar O, Shertzer O, Bloch G. Bumble Bees ( Bombus terrestris) Use Time-Memory to Associate Reward with Color and Time of Day. INSECTS 2023; 14:707. [PMID: 37623417 PMCID: PMC10455649 DOI: 10.3390/insects14080707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023]
Abstract
Circadian clocks regulate ecologically important complex behaviors in honey bees, but it is not clear whether similar capacities exist in other species of bees. One key behavior influenced by circadian clocks is time-memory, which enables foraging bees to precisely time flower visitation to periods of maximal pollen or nectar availability and reduces the costs of visiting a non-rewarding flower patch. Bumble bees live in smaller societies and typically forage over shorter distances than honey bees, and it is therefore not clear whether they can similarly associate reward with time of day. We trained individually marked bumble bee (Bombus terrestris) workers to forage for sugar syrup in a flight cage with yellow or blue feeders rewarding either during the morning or evening. After training for over two weeks, we recorded all visitations to colored feeders filled with only water. We performed two experiments, each with a different colony. We found that bees tended to show higher foraging activity during the morning and evening training sessions compared to other times during the day. During the test day, the trained bees were more likely to visit the rewarding rather than the non-rewarding colored feeders at the same time of day during the test sessions, indicating that they associated time of day and color with the sugar syrup reward. These observations lend credence to the hypothesis that bumble bees have efficient time-memory, indicating that this complex behavior is not limited to honey bees that evolved sophisticated social foraging behaviors over large distances.
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Affiliation(s)
- Ozlem Gonulkirmaz-Cancalar
- Department of Ecology, Evolution, and Behavior, The Alexander A. Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel; (O.G.-C.); (O.S.)
| | - Oded Shertzer
- Department of Ecology, Evolution, and Behavior, The Alexander A. Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel; (O.G.-C.); (O.S.)
| | - Guy Bloch
- Department of Ecology, Evolution, and Behavior, The Alexander A. Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel; (O.G.-C.); (O.S.)
- The Federmann Center for the Study of Rationality, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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6
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Yin JCP, Cui E, Hardin PE, Zhou H. Circadian disruption of memory consolidation in Drosophila. Front Syst Neurosci 2023; 17:1129152. [PMID: 37034015 PMCID: PMC10073699 DOI: 10.3389/fnsys.2023.1129152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
The role of the circadian system in memory formation is an important question in neurobiology. Despite this hypothesis being intuitively appealing, the existing data is confusing. Recent work in Drosophila has helped to clarify certain aspects of the problem, but the emerging sense is that the likely mechanisms are more complex than originally conceptualized. In this report, we identify a post-training window of time (during consolidation) when the circadian clock and its components are involved in memory formation. In the broader context, our data suggest that circadian biology might have multiple roles during memory formation. Testing for its roles at multiple timepoints, and in different cells, will be necessary to resolve some of the conflicting data.
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Affiliation(s)
- Jerry C. P. Yin
- Laboratory of Genetics, School of Medicine and Public Health, University of Wisconsin—Madison, Madison, WI, United States
- Neurology Department, School of Medicine and Public Health, University of Wisconsin—Madison, Madison, WI, United States
- *Correspondence: Jerry C. P. Yin
| | - Ethan Cui
- Laboratory of Genetics, School of Medicine and Public Health, University of Wisconsin—Madison, Madison, WI, United States
| | - Paul E. Hardin
- Department of Biology and Center for Biological Clocks Research, Texas A&M University, College Station, College Station, TX, United States
| | - Hong Zhou
- Laboratory of Genetics, School of Medicine and Public Health, University of Wisconsin—Madison, Madison, WI, United States
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7
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Machado Almeida P, Lago Solis B, Stickley L, Feidler A, Nagoshi E. Neurofibromin 1 in mushroom body neurons mediates circadian wake drive through activating cAMP-PKA signaling. Nat Commun 2021; 12:5758. [PMID: 34599173 PMCID: PMC8486785 DOI: 10.1038/s41467-021-26031-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 09/15/2021] [Indexed: 02/08/2023] Open
Abstract
Various behavioral and cognitive states exhibit circadian variations in animals across phyla including Drosophila melanogaster, in which only ~0.1% of the brain's neurons contain circadian clocks. Clock neurons transmit the timing information to a plethora of non-clock neurons via poorly understood mechanisms. Here, we address the molecular underpinning of this phenomenon by profiling circadian gene expression in non-clock neurons that constitute the mushroom body, the center of associative learning and sleep regulation. We show that circadian clocks drive rhythmic expression of hundreds of genes in mushroom body neurons, including the Neurofibromin 1 (Nf1) tumor suppressor gene and Pka-C1. Circadian clocks also drive calcium rhythms in mushroom body neurons via NF1-cAMP/PKA-C1 signaling, eliciting higher mushroom body activity during the day than at night, thereby promoting daytime wakefulness. These findings reveal the pervasive, non-cell-autonomous circadian regulation of gene expression in the brain and its role in sleep.
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Affiliation(s)
- Pedro Machado Almeida
- grid.8591.50000 0001 2322 4988Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, Geneva, 4, CH-1211 Switzerland
| | - Blanca Lago Solis
- grid.8591.50000 0001 2322 4988Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, Geneva, 4, CH-1211 Switzerland
| | - Luca Stickley
- grid.8591.50000 0001 2322 4988Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, Geneva, 4, CH-1211 Switzerland
| | - Alexis Feidler
- grid.8591.50000 0001 2322 4988Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, Geneva, 4, CH-1211 Switzerland ,grid.412750.50000 0004 1936 9166Present Address: University of Rochester School of Medicine and Dentistry, Rochester, NY USA
| | - Emi Nagoshi
- grid.8591.50000 0001 2322 4988Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, Geneva, 4, CH-1211 Switzerland
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8
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Ikarashi M, Tanimoto H. Drosophila acquires seconds-scale rhythmic behavior. J Exp Biol 2021; 224:238112. [PMID: 33795422 DOI: 10.1242/jeb.242443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 03/22/2021] [Indexed: 11/20/2022]
Abstract
Detection of the temporal structure of stimuli is crucial for prediction. While perception of interval timing is relevant for immediate behavioral adaptations, it has scarcely been investigated, especially in invertebrates. Here, we examined whether the fruit fly, Drosophila melanogaster, can acquire rhythmic behavior in the range of seconds. To this end, we developed a novel temporal conditioning paradigm utilizing repeated electric shocks. Combined automatic behavioral annotation and time-frequency analysis revealed that behavioral rhythms continued after cessation of the shocks. Furthermore, we found that aging impaired interval timing. This study thus not only demonstrates the ability of insects to acquire behavioral rhythms of a few seconds, but highlights a life-course decline of temporal coordination, which is also common in mammals.
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Affiliation(s)
- Masayoshi Ikarashi
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Hiromu Tanimoto
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
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9
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Tasman K, Rands SA, Hodge JJL. The Power of Drosophila melanogaster for Modeling Neonicotinoid Effects on Pollinators and Identifying Novel Mechanisms. Front Physiol 2021; 12:659440. [PMID: 33967830 PMCID: PMC8096932 DOI: 10.3389/fphys.2021.659440] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/29/2021] [Indexed: 02/06/2023] Open
Abstract
Neonicotinoids are the most widely used insecticides in the world and are implicated in the widespread population declines of insects including pollinators. Neonicotinoids target nicotinic acetylcholine receptors which are expressed throughout the insect central nervous system, causing a wide range of sub-lethal effects on non-target insects. Here, we review the potential of the fruit fly Drosophila melanogaster to model the sub-lethal effects of neonicotinoids on pollinators, by utilizing its well-established assays that allow rapid identification and mechanistic characterization of these effects. We compare studies on the effects of neonicotinoids on lethality, reproduction, locomotion, immunity, learning, circadian rhythms and sleep in D. melanogaster and a range of pollinators. We also highlight how the genetic tools available in D. melanogaster, such as GAL4/UAS targeted transgene expression system combined with RNAi lines to any gene in the genome including the different nicotinic acetylcholine receptor subunit genes, are set to elucidate the mechanisms that underlie the sub-lethal effects of these common pesticides. We argue that studying pollinators and D. melanogaster in tandem allows rapid elucidation of mechanisms of action, which translate well from D. melanogaster to pollinators. We focus on the recent identification of novel and important sublethal effects of neonicotinoids on circadian rhythms and sleep. The comparison of effects between D. melanogaster and pollinators and the use of genetic tools to identify mechanisms make a powerful partnership for the future discovery and testing of more specific insecticides.
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Affiliation(s)
- Kiah Tasman
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Sean A. Rands
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - James J. L. Hodge
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
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10
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Neonicotinoids disrupt memory, circadian behaviour and sleep. Sci Rep 2021; 11:2061. [PMID: 33479461 PMCID: PMC7820356 DOI: 10.1038/s41598-021-81548-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/28/2020] [Indexed: 02/06/2023] Open
Abstract
Globally, neonicotinoids are the most used insecticides, despite their well-documented sub-lethal effects on beneficial insects. Neonicotinoids are nicotinic acetylcholine receptor agonists. Memory, circadian rhythmicity and sleep are essential for efficient foraging and pollination and require nicotinic acetylcholine receptor signalling. The effect of field-relevant concentrations of the European Union-banned neonicotinoids: imidacloprid, clothianidin, thiamethoxam and thiacloprid were tested on Drosophila memory, circadian rhythms and sleep. Field-relevant concentrations of imidacloprid, clothianidin and thiamethoxam disrupted learning, behavioural rhythmicity and sleep whilst thiacloprid exposure only affected sleep. Exposure to imidacloprid and clothianidin prevented the day/night remodelling and accumulation of pigment dispersing factor (PDF) neuropeptide in the dorsal terminals of clock neurons. Knockdown of the neonicotinoid susceptible Dα1 and Dβ2 nicotinic acetylcholine receptor subunits in the mushroom bodies or clock neurons recapitulated the neonicotinoid like deficits in memory or sleep/circadian behaviour respectively. Disruption of learning, circadian rhythmicity and sleep are likely to have far-reaching detrimental effects on beneficial insects in the field.
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11
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Beer K, Helfrich-Förster C. Model and Non-model Insects in Chronobiology. Front Behav Neurosci 2020; 14:601676. [PMID: 33328925 PMCID: PMC7732648 DOI: 10.3389/fnbeh.2020.601676] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 10/30/2020] [Indexed: 12/20/2022] Open
Abstract
The fruit fly Drosophila melanogaster is an established model organism in chronobiology, because genetic manipulation and breeding in the laboratory are easy. The circadian clock neuroanatomy in D. melanogaster is one of the best-known clock networks in insects and basic circadian behavior has been characterized in detail in this insect. Another model in chronobiology is the honey bee Apis mellifera, of which diurnal foraging behavior has been described already in the early twentieth century. A. mellifera hallmarks the research on the interplay between the clock and sociality and complex behaviors like sun compass navigation and time-place-learning. Nevertheless, there are aspects of clock structure and function, like for example the role of the clock in photoperiodism and diapause, which can be only insufficiently investigated in these two models. Unlike high-latitude flies such as Chymomyza costata or D. ezoana, cosmopolitan D. melanogaster flies do not display a photoperiodic diapause. Similarly, A. mellifera bees do not go into "real" diapause, but most solitary bee species exhibit an obligatory diapause. Furthermore, sociality evolved in different Hymenoptera independently, wherefore it might be misleading to study the social clock only in one social insect. Consequently, additional research on non-model insects is required to understand the circadian clock in Diptera and Hymenoptera. In this review, we introduce the two chronobiology model insects D. melanogaster and A. mellifera, compare them with other insects and show their advantages and limitations as general models for insect circadian clocks.
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Affiliation(s)
- Katharina Beer
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocentre, Am Hubland, University of Würzburg, Würzburg, Germany
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12
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Flyer-Adams JG, Rivera-Rodriguez EJ, Yu J, Mardovin JD, Reed ML, Griffith LC. Regulation of Olfactory Associative Memory by the Circadian Clock Output Signal Pigment-Dispersing Factor (PDF). J Neurosci 2020; 40:9066-9077. [PMID: 33106351 PMCID: PMC7673005 DOI: 10.1523/jneurosci.0782-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 08/10/2020] [Accepted: 09/07/2020] [Indexed: 01/19/2023] Open
Abstract
Dissociation between the output of the circadian clock and external environmental cues is a major cause of human cognitive dysfunction. While the effects of ablation of the molecular clock on memory have been studied in many systems, little has been done to test the role of specific clock circuit output signals. To address this gap, we examined the effects of mutations of Pigment-dispersing factor (Pdf) and its receptor, Pdfr, on associative memory in male and female Drosophila Loss of PDF signaling significantly decreases the ability to form associative memory. Appetitive short-term memory (STM), which in wild-type (WT) is time-of-day (TOD) independent, is decreased across the day by mutation of Pdf or Pdfr, but more substantially in the morning than in the evening. This defect is because of PDFR expression in adult neurons outside the core clock circuit and the mushroom body (MB) Kenyon cells (KCs). The acquisition of a TOD difference in mutants implies the existence of multiple oscillators that act to normalize memory formation across the day for appetitive processes. Interestingly, aversive STM requires PDF but not PDFR, suggesting that there are valence-specific pathways downstream of PDF that regulate memory formation. These data argue that the circadian clock uses circuit-specific and molecularly diverse output pathways to enhance the ability of animals to optimize responses to changing conditions.SIGNIFICANCE STATEMENT From humans to invertebrates, cognitive processes are influenced by organisms' internal circadian clocks, the pace of which is linked to the solar cycle. Disruption of this link is increasingly common (e.g., jetlag, social jetlag disorders) and causes cognitive impairments that are costly and long lasting. A detailed understanding of how the internal clock regulates cognition is critical for the development of therapeutic methods. Here, we show for the first time that olfactory associative memory in Drosophila requires signaling by Pigment-dispersing factor (PDF), a neuromodulatory signaling peptide produced only by circadian clock circuit neurons. We also find a novel role for the clock circuit in stabilizing appetitive sucrose/odor memory across the day.
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Affiliation(s)
- Johanna G Flyer-Adams
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Emmanuel J Rivera-Rodriguez
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Junwei Yu
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Jacob D Mardovin
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Martha L Reed
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Leslie C Griffith
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
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13
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Toure MW, Young FJ, McMillan WO, Montgomery SH. Heliconiini butterflies can learn time-dependent reward associations. Biol Lett 2020; 16:20200424. [PMID: 32961092 PMCID: PMC7532716 DOI: 10.1098/rsbl.2020.0424] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
For many pollinators, flowers provide predictable temporal schedules of resource availability, meaning an ability to learn time-dependent information could be widely beneficial. However, this ability has only been demonstrated in a handful of species. Observations of Heliconius butterflies suggest that they may have an ability to form time-dependent foraging preferences. Heliconius are unique among butterflies in actively collecting pollen, a dietary behaviour linked to spatio-temporally faithful ‘trap-line' foraging. Time dependency of foraging preferences is hypothesized to allow Heliconius to exploit temporal predictability in alternative pollen resources. Here, we provide the first experimental evidence in support of this hypothesis, demonstrating that Heliconius hecale can learn opposing colour preferences in two time periods. This shift in preference is robust to the order of presentation, suggesting that preference is tied to the time of day and not due to ordinal or interval learning. However, this ability is not limited to Heliconius, as previously hypothesized, but also present in a related genus of non-pollen feeding butterflies. This demonstrates time learning likely pre-dates the origin of pollen feeding and may be prevalent across butterflies with less specialized foraging behaviours.
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Affiliation(s)
- M Wyatt Toure
- Department of Biology, McGill University, 1205 Docteur Penfield, Montreal, Canada H3A 1B1.,Smithsonian Tropical Research Institute, Gamboa, Panama
| | - Fletcher J Young
- Smithsonian Tropical Research Institute, Gamboa, Panama.,Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.,School of Biological Science, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | | | - Stephen H Montgomery
- Smithsonian Tropical Research Institute, Gamboa, Panama.,School of Biological Science, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
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14
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Molecular mechanisms and physiological importance of circadian rhythms. Nat Rev Mol Cell Biol 2019; 21:67-84. [PMID: 31768006 DOI: 10.1038/s41580-019-0179-2] [Citation(s) in RCA: 746] [Impact Index Per Article: 124.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2019] [Indexed: 12/12/2022]
Abstract
To accommodate daily recurring environmental changes, animals show cyclic variations in behaviour and physiology, which include prominent behavioural states such as sleep-wake cycles but also a host of less conspicuous oscillations in neurological, metabolic, endocrine, cardiovascular and immune functions. Circadian rhythmicity is created endogenously by genetically encoded molecular clocks, whose components cooperate to generate cyclic changes in their own abundance and activity, with a periodicity of about a day. Throughout the body, such molecular clocks convey temporal control to the function of organs and tissues by regulating pertinent downstream programmes. Synchrony between the different circadian oscillators and resonance with the solar day is largely enabled by a neural pacemaker, which is directly responsive to certain environmental cues and able to transmit internal time-of-day representations to the entire body. In this Review, we discuss aspects of the circadian clock in Drosophila melanogaster and mammals, including the components of these molecular oscillators, the function and mechanisms of action of central and peripheral clocks, their synchronization and their relevance to human health.
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15
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Mancini N, Hranova S, Weber J, Weiglein A, Schleyer M, Weber D, Thum AS, Gerber B. Reversal learning in Drosophila larvae. Learn Mem 2019; 26:424-435. [PMID: 31615854 PMCID: PMC6796787 DOI: 10.1101/lm.049510.119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 08/09/2019] [Indexed: 01/08/2023]
Abstract
Adjusting behavior to changed environmental contingencies is critical for survival, and reversal learning provides an experimental handle on such cognitive flexibility. Here, we investigate reversal learning in larval Drosophila Using odor-taste associations, we establish olfactory reversal learning in the appetitive and the aversive domain, using either fructose as a reward or high-concentration sodium chloride as a punishment, respectively. Reversal learning is demonstrated both in differential and in absolute conditioning, in either valence domain. In differential conditioning, the animals are first trained such that an odor A is paired, for example, with the reward whereas odor B is not (A+/B); this is followed by a second training phase with reversed contingencies (A/B+). In absolute conditioning, odor B is omitted, such that the animals are first trained with paired presentations of A and reward, followed by unpaired training in the second training phase. Our results reveal "true" reversal learning in that the opposite associative effects of both the first and the second training phase are detectable after reversed-contingency training. In what is a surprisingly quick, one-trial contingency adjustment in the Drosophila larva, the present study establishes a simple and genetically easy accessible study case of cognitive flexibility.
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Affiliation(s)
- Nino Mancini
- Department of Genetics, Leibniz Institute for Neurobiology (LIN), 39118 Magdeburg, Germany
| | - Sia Hranova
- Institute for Biology, University of Leipzig, 04103 Leipzig, Germany
| | - Julia Weber
- Department of Genetics, Leibniz Institute for Neurobiology (LIN), 39118 Magdeburg, Germany
| | - Aliće Weiglein
- Department of Genetics, Leibniz Institute for Neurobiology (LIN), 39118 Magdeburg, Germany
| | - Michael Schleyer
- Department of Genetics, Leibniz Institute for Neurobiology (LIN), 39118 Magdeburg, Germany
| | - Denise Weber
- Institute for Biology, University of Leipzig, 04103 Leipzig, Germany
| | - Andreas S Thum
- Institute for Biology, University of Leipzig, 04103 Leipzig, Germany
| | - Bertram Gerber
- Department of Genetics, Leibniz Institute for Neurobiology (LIN), 39118 Magdeburg, Germany
- Institute for Biology, Otto von Guericke University, 39106 Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
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16
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Horn M, Mitesser O, Hovestadt T, Yoshii T, Rieger D, Helfrich-Förster C. The Circadian Clock Improves Fitness in the Fruit Fly, Drosophila melanogaster. Front Physiol 2019; 10:1374. [PMID: 31736790 PMCID: PMC6838225 DOI: 10.3389/fphys.2019.01374] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 10/17/2019] [Indexed: 12/17/2022] Open
Abstract
It is assumed that a properly timed circadian clock enhances fitness, but only few studies have truly demonstrated this in animals. We raised each of the three classical Drosophila period mutants for >50 generations in the laboratory in competition with wildtype flies. The populations were either kept under a conventional 24-h day or under cycles that matched the mutant’s natural cycle, i.e., a 19-h day in the case of pers mutants and a 29-h day for perl mutants. The arrhythmic per0 mutants were grown together with wildtype flies under constant light that renders wildtype flies similar arrhythmic as the mutants. In addition, the mutants had to compete with wildtype flies for two summers in two consecutive years under outdoor conditions. We found that wildtype flies quickly outcompeted the mutant flies under the 24-h laboratory day and under outdoor conditions, but perl mutants persisted and even outnumbered the wildtype flies under the 29-h day in the laboratory. In contrast, pers and per0 mutants did not win against wildtype flies under the 19-h day and constant light, respectively. Our results demonstrate that wildtype flies have a clear fitness advantage in terms of fertility and offspring survival over the period mutants and – as revealed for perl mutants – this advantage appears maximal when the endogenous period resonates with the period of the environment. However, the experiments indicate that perl and pers persist at low frequencies in the population even under the 24-h day. This may be a consequence of a certain mating preference of wildtype and heterozygous females for mutant males and time differences in activity patterns between wildtype and mutants.
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Affiliation(s)
- Melanie Horn
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, Julius-Maximilians University Würzburg, Würzburg, Germany
| | - Oliver Mitesser
- Theoretical Evolutionary Ecology Group, Biocenter, Department of Animal Ecology and Tropical Biology, Julius-Maximilians University Würzburg, Würzburg, Germany
| | - Thomas Hovestadt
- Theoretical Evolutionary Ecology Group, Biocenter, Department of Animal Ecology and Tropical Biology, Julius-Maximilians University Würzburg, Würzburg, Germany
| | - Taishi Yoshii
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Dirk Rieger
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, Julius-Maximilians University Würzburg, Würzburg, Germany
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, Julius-Maximilians University Würzburg, Würzburg, Germany
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17
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Pírez N, Bernabei-Cornejo SG, Fernandez-Acosta M, Duhart JM, Ceriani MF. Contribution of non-circadian neurons to the temporal organization of locomotor activity. Biol Open 2019; 8:bio.039628. [PMID: 30530810 PMCID: PMC6361196 DOI: 10.1242/bio.039628] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In the fruit fly, Drosophila melanogaster, the daily cycle of rest and activity is a rhythmic behavior that relies on the activity of a small number of neurons. The small ventral lateral neurons (sLNvs) are considered key in the control of locomotor rhythmicity. Previous work from our laboratory has showed that these neurons undergo structural remodeling on their axonal projections on a daily basis. Such remodeling endows sLNvs with the possibility to make synaptic contacts with different partners at different times throughout the day, as has been previously described. By using different genetic tools to alter membrane excitability of the sLNv putative postsynaptic partners, we tested their functional role in the control of locomotor activity. We also used optical imaging to test the functionality of these contacts. We found that these different neuronal groups affect the consolidation of rhythmic activity, suggesting that non-circadian cells are part of the circuit that controls locomotor activity. Our results suggest that new neuronal groups, in addition to the well-characterized clock neurons, contribute to the operations of the circadian network that controls locomotor activity in D. melanogaster. Summary: Here we characterized the impact of different putative postsynaptic partners of the sLNvs on the control of rhythmic locomotor behavior. We found that some of these novel neuronal clusters are relevant for the control of locomotor activity.
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Affiliation(s)
- Nicolás Pírez
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas-Buenos Aires (IIB-BA, CONICET), 1425 Buenos Aires, Argentina
| | - Sofia G Bernabei-Cornejo
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas-Buenos Aires (IIB-BA, CONICET), 1425 Buenos Aires, Argentina
| | - Magdalena Fernandez-Acosta
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas-Buenos Aires (IIB-BA, CONICET), 1425 Buenos Aires, Argentina
| | - José M Duhart
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas-Buenos Aires (IIB-BA, CONICET), 1425 Buenos Aires, Argentina
| | - M Fernanda Ceriani
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas-Buenos Aires (IIB-BA, CONICET), 1425 Buenos Aires, Argentina
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18
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Fropf R, Zhou H, Yin JCP. The clock gene period differentially regulates sleep and memory in Drosophila. Neurobiol Learn Mem 2018; 153:2-12. [PMID: 29474956 PMCID: PMC6064670 DOI: 10.1016/j.nlm.2018.02.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 01/20/2018] [Accepted: 02/19/2018] [Indexed: 11/21/2022]
Abstract
Circadian regulation is a conserved phenomenon across the animal kingdom, and its disruption can have severe behavioral and physiological consequences. Core circadian clock proteins are likewise well conserved from Drosophila to humans. While the molecular clock interactions that regulate circadian rhythms have been extensively described, additional roles for clock genes during complex behaviors are less understood. Here, we show that mutations in the clock gene period result in differential time-of-day effects on acquisition and long-term memory of aversive olfactory conditioning. Sleep is also altered in period mutants: while its overall levels don't correlate with memory, sleep plasticity in different genotypes correlates with immediate performance after training. We further describe distinct anatomical bases for Period function by manipulating Period activity in restricted brain cells and testing the effects on specific aspects of memory and sleep. In the null mutant background, different features of sleep and memory are affected when we reintroduce a form of the period gene in glia, lateral neurons, and the fan-shaped body. Our results indicate that the role of the clock gene period may be separable in specific aspects of sleep or memory; further studies into the molecular mechanisms of these processes suggest independent neural circuits and molecular cascades that mediate connections between the distinct phenomena.
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Affiliation(s)
- Robin Fropf
- Neuroscience Training Program, 1300 University Ave., University of Wisconsin-Madison, Madison, WI 53706, United States.
| | - Hong Zhou
- Laboratory of Genetics, 3434 Genetics/Biotechnology, 425 Henry Mall, University of Wisconsin-Madison, Madison, WI 53706, United States.
| | - Jerry C P Yin
- Laboratory of Genetics, 3434 Genetics/Biotechnology, 425 Henry Mall, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Neurology, School of Medicine and Public Health, University of Wisconsin-Madison, 1685 Highland Ave., Madison, WI 53706, United States.
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19
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Schubert FK, Hagedorn N, Yoshii T, Helfrich-Förster C, Rieger D. Neuroanatomical details of the lateral neurons of Drosophila melanogaster support their functional role in the circadian system. J Comp Neurol 2018; 526:1209-1231. [PMID: 29424420 PMCID: PMC5873451 DOI: 10.1002/cne.24406] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/30/2018] [Accepted: 01/30/2018] [Indexed: 12/29/2022]
Abstract
Drosophila melanogaster is a long‐standing model organism in the circadian clock research. A major advantage is the relative small number of about 150 neurons, which built the circadian clock in Drosophila. In our recent work, we focused on the neuroanatomical properties of the lateral neurons of the clock network. By applying the multicolor‐labeling technique Flybow we were able to identify the anatomical similarity of the previously described E2 subunit of the evening oscillator of the clock, which is built by the 5th small ventrolateral neuron (5th s‐LNv) and one ITP positive dorsolateral neuron (LNd). These two clock neurons share the same spatial and functional properties. We found both neurons innervating the same brain areas with similar pre‐ and postsynaptic sites in the brain. Here the anatomical findings support their shared function as a main evening oscillator in the clock network like also found in previous studies. A second quite surprising finding addresses the large lateral ventral PDF‐neurons (l‐LNvs). We could show that the four hardly distinguishable l‐LNvs consist of two subgroups with different innervation patterns. While three of the neurons reflect the well‐known branching pattern reproduced by PDF immunohistochemistry, one neuron per brain hemisphere has a distinguished innervation profile and is restricted only to the proximal part of the medulla‐surface. We named this neuron “extra” l‐LNv (l‐LNvx). We suggest the anatomical findings reflect different functional properties of the two l‐LNv subgroups.
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Affiliation(s)
- Frank K Schubert
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, 97074, Germany
| | - Nicolas Hagedorn
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, 97074, Germany
| | - Taishi Yoshii
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, 97074, Germany
| | - Dirk Rieger
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, 97074, Germany
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20
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Jarabo P, Martin FA. Neurogenetics of Drosophila circadian clock: expect the unexpected. J Neurogenet 2017; 31:250-265. [DOI: 10.1080/01677063.2017.1370466] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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21
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Chouhan NS, Wolf R, Heisenberg M. Starvation promotes odor/feeding-time associations in flies. ACTA ACUST UNITED AC 2017; 24:318-321. [PMID: 28620079 PMCID: PMC5473106 DOI: 10.1101/lm.045039.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/25/2017] [Indexed: 11/24/2022]
Abstract
Starvation causes a motivational state that facilitates diverse behaviors such as feeding, walking, and search. Starved Drosophila can form odor/feeding-time associations but the role of starvation in encoding of “time” is poorly understood. Here we show that the extent of starvation is correlated with the fly's ability to establish odor/feeding-time memories. Prolonged starvation promotes odor/feeding-time associations after just a single cycle of reciprocal training. We also show that starvation is required for acquisition but is dispensable for retrieval of odor/feeding-time memory. Finally, even with extended starvation, a functional circadian oscillator is indispensable for establishing odor/feeding-time memories.
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22
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Harbour seals (Phoca vitulina) are able to time precisely. Anim Cogn 2016; 19:1133-1142. [DOI: 10.1007/s10071-016-1020-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/04/2016] [Accepted: 08/01/2016] [Indexed: 10/21/2022]
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