1
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Wei T, Guo Q, Webb B. Learning with sparse reward in a gap junction network inspired by the insect mushroom body. PLoS Comput Biol 2024; 20:e1012086. [PMID: 38781280 DOI: 10.1371/journal.pcbi.1012086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/05/2024] [Accepted: 04/17/2024] [Indexed: 05/25/2024] Open
Abstract
Animals can learn in real-life scenarios where rewards are often only available when a goal is achieved. This 'distal' or 'sparse' reward problem remains a challenge for conventional reinforcement learning algorithms. Here we investigate an algorithm for learning in such scenarios, inspired by the possibility that axo-axonal gap junction connections, observed in neural circuits with parallel fibres such as the insect mushroom body, could form a resistive network. In such a network, an active node represents the task state, connections between nodes represent state transitions and their connection to actions, and current flow to a target state can guide decision making. Building on evidence that gap junction weights are adaptive, we propose that experience of a task can modulate the connections to form a graph encoding the task structure. We demonstrate that the approach can be used for efficient reinforcement learning under sparse rewards, and discuss whether it is plausible as an account of the insect mushroom body.
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Affiliation(s)
- Tianqi Wei
- Institute of Perception, Action, and Behaviour, School of Informatics, University of Edinburgh, Edinburgh, United Kingdom
- School of Artificial Intelligence, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Qinghai Guo
- Huawei Technologies Co., Ltd., Shenzhen, Guangdong, China
| | - Barbara Webb
- Institute of Perception, Action, and Behaviour, School of Informatics, University of Edinburgh, Edinburgh, United Kingdom
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2
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Fiala A, Kaun KR. What do the mushroom bodies do for the insect brain? Twenty-five years of progress. Learn Mem 2024; 31:a053827. [PMID: 38862175 PMCID: PMC11199942 DOI: 10.1101/lm.053827.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Accepted: 04/22/2024] [Indexed: 06/13/2024]
Abstract
In 1998, a special edition of Learning & Memory was published with a discrete focus of synthesizing the state of the field to provide an overview of the function of the insect mushroom body. While molecular neuroscience and optical imaging of larger brain areas were advancing, understanding the basic functioning of neuronal circuits, particularly in the context of the mushroom body, was rudimentary. In the past 25 years, technological innovations have allowed researchers to map and understand the in vivo function of the neuronal circuits of the mushroom body system, making it an ideal model for investigating the circuit basis of sensory encoding, memory formation, and behavioral decisions. Collaborative efforts within the community have played a crucial role, leading to an interactive connectome of the mushroom body and accessible genetic tools for studying mushroom body circuit function. Looking ahead, continued technological innovation and collaborative efforts are likely to further advance our understanding of the mushroom body and its role in behavior and cognition, providing insights that generalize to other brain structures and species.
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Affiliation(s)
- André Fiala
- Department of Molecular Neurobiology of Behaviour, University of Göttingen, Göttingen 37077, Germany
| | - Karla R Kaun
- Department of Neuroscience, Brown University, Providence, Rhode Island 02806, USA
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3
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Zerva MC, Triantafylloudis C, Paspaliaris V, Skoulakis EMC, Papanikolopoulou K. Choline Metabolites Reverse Differentially the Habituation Deficit and Elevated Memory of Tau Null Drosophila. Cells 2024; 13:746. [PMID: 38727282 PMCID: PMC11083674 DOI: 10.3390/cells13090746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024] Open
Abstract
Impaired neuronal plasticity and cognitive decline are cardinal features of Alzheimer's disease and related Tauopathies. Aberrantly modified Tau protein and neurotransmitter imbalance, predominantly involving acetylcholine, have been linked to these symptoms. In Drosophila, we have shown that dTau loss specifically enhances associative long-term olfactory memory, impairs foot shock habituation, and deregulates proteins involved in the regulation of neurotransmitter levels, particularly acetylcholine. Interestingly, upon choline treatment, the habituation and memory performance of mutants are restored to that of control flies. Based on these surprising results, we decided to use our well-established genetic model to understand how habituation deficits and memory performance correlate with different aspects of choline physiology as an essential component of the neurotransmitter acetylcholine, the lipid phosphatidylcholine, and the osmoregulator betaine. The results revealed that the two observed phenotypes are reversed by different choline metabolites, implying that they are governed by different underlying mechanisms. This work can contribute to a broader knowledge about the physiologic function of Tau, which may be translated into understanding the mechanisms of Tauopathies.
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Affiliation(s)
- Maria-Christina Zerva
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre “Alexander Fleming”, 16672 Vari, Greece (V.P.)
- Athens International Master’s Program in Neurosciences, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - Christos Triantafylloudis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre “Alexander Fleming”, 16672 Vari, Greece (V.P.)
- Master’s Program in Molecular Biomedicine, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Vassilis Paspaliaris
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre “Alexander Fleming”, 16672 Vari, Greece (V.P.)
- Laboratory of Experimental Physiology, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Efthimios M. C. Skoulakis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre “Alexander Fleming”, 16672 Vari, Greece (V.P.)
| | - Katerina Papanikolopoulou
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre “Alexander Fleming”, 16672 Vari, Greece (V.P.)
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4
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Nöbel S, Danchin E, Isabel G. Mate copying requires the coincidence detector Rutabaga in the mushroom bodies of Drosophila melanogaster. iScience 2023; 26:107682. [PMID: 37694137 PMCID: PMC10484988 DOI: 10.1016/j.isci.2023.107682] [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: 03/28/2023] [Revised: 07/03/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023] Open
Abstract
Mate choice constitutes a major fitness-affecting decision often involving social learning leading to copying the preference of other individuals (i.e., mate copying). While mate copying exists in many taxa, its underlying neurobiological mechanisms remain virtually unknown. Here, we show in Drosophila melanogaster that the rutabaga gene is necessary to support mate copying. Rutabaga encodes an adenylyl cyclase (AC-Rut+) acting as a coincidence detector in associative learning. Since the brain localization requirements for AC-Rut+ expression differ in classical and operant learning, we determine the functional localization of AC-Rut+ for mate copying by artificially rescuing the expression of AC-Rut+ in neural subsets of a rutabaga mutant. We found that AC-Rut+ has to be expressed in the mushroom bodies' Kenyon cells (KCs), specifically in the γ-KCs subset. Thus, this form of discriminative social learning requires the same KCs as non-social Pavlovian learning, suggesting that pathways of social and asocial learning overlap significantly.
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Affiliation(s)
- Sabine Nöbel
- Department of Zoology, Animal Ecology, Martin-Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
- Université Toulouse 1 Capitole and Institute for Advanced Study in Toulouse (IAST), Toulouse, France
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Etienne Danchin
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 118 route de Narbonne, 31062 Toulouse, France
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), CNRS UMR 5169, Université de Toulouse Midi-Pyrénées, Toulouse, France
| | - Guillaume Isabel
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), CNRS UMR 5169, Université de Toulouse Midi-Pyrénées, Toulouse, France
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5
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Chen CC, Lin HW, Feng KL, Tseng DW, de Belle JS, Chiang AS. A subset of cholinergic mushroom body neurons blocks long-term memory formation in Drosophila. Cell Rep 2023; 42:112974. [PMID: 37590142 DOI: 10.1016/j.celrep.2023.112974] [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: 07/23/2022] [Revised: 12/22/2022] [Accepted: 07/29/2023] [Indexed: 08/19/2023] Open
Abstract
Long-term memory (LTM) requires learning-induced synthesis of new proteins allocated to specific neurons and synapses in a neural circuit. Not all learned information, however, becomes permanent memory. How the brain gates relevant information into LTM remains unclear. In Drosophila adults, weak learning after a single training session in an olfactory aversive task typically does not induce protein-synthesis-dependent LTM. Instead, strong learning after multiple spaced training sessions is required. Here, we report that pre-synaptic active-zone protein synthesis and cholinergic signaling from the early α/β subset of mushroom body (MB) neurons produce a downstream inhibitory effect on LTM formation. When we eliminated inhibitory signaling from these neurons, weak learning was then sufficient to form LTM. This bidirectional circuit mechanism modulates the transition between distinct memory phase functions in different subpopulations of MB neurons in the olfactory memory circuit.
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Affiliation(s)
- Chun-Chao Chen
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Hsuan-Wen Lin
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Kuan-Lin Feng
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Der-Wan Tseng
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - J Steven de Belle
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan; School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA; Department of Psychological Sciences, University of San Diego, San Diego, CA 92110, USA; School of Life Sciences, University of Nevada, Las Vegas, NV 89154, USA; MnemOdyssey LLC, Escondido, CA 92027, USA
| | - Ann-Shyn Chiang
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan; Institute of Systems Neuroscience and Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan; Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80780, Taiwan; Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli 35053, Taiwan; Graduate Institute of Clinical Medical Science, China Medical University, Taichung 40402, Taiwan; Kavli Institute for Brain and Mind, University of California at San Diego, La Jolla, CA 92093-0526, USA.
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6
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Wang Z, Chang Z, Liu Z, Zhang S. Influences of Microbial Symbionts on Chemoreception of Their Insect Hosts. INSECTS 2023; 14:638. [PMID: 37504644 PMCID: PMC10380252 DOI: 10.3390/insects14070638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/09/2023] [Accepted: 07/13/2023] [Indexed: 07/29/2023]
Abstract
Chemical communication is widespread among insects and exploited to adjust their behavior, such as food and habitat seeking and preferences, recruitment, defense, and mate attraction. Recently, many studies have revealed that microbial symbionts could regulate host chemical communication by affecting the synthesis and perception of insect semiochemicals. In this paper, we review recent studies of the influence of microbial symbionts on insect chemoreception. Microbial symbionts may influence insect sensitivity to semiochemicals by regulating the synthesis of odorant-binding proteins or chemosensory proteins and olfactory or gustatory receptors and regulating host neurotransmission, thereby adjusting insect behavior. The manipulation of insect chemosensory behavior by microbial symbionts is conducive to their proliferation and dispersal and provides the impetus for insects to change their feeding habits and aggregation and dispersal behavior, which contributes to population differentiation in insects. Future research is necessary to reveal the material and information exchange between both partners to improve our comprehension of the evolution of chemoreception in insects. Manipulating insect chemoreception physiology by inoculating them with microbes could be utilized as a potential approach to managing insect populations.
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Affiliation(s)
- Zhengyan Wang
- School of Food and Strategic Reserves, Henan University of Technology, Zhengzhou 450001, China
| | - Zhenzhen Chang
- School of Food and Strategic Reserves, Henan University of Technology, Zhengzhou 450001, China
| | - Zhiyuan Liu
- School of Food and Strategic Reserves, Henan University of Technology, Zhengzhou 450001, China
| | - Shan Zhang
- School of Food and Strategic Reserves, Henan University of Technology, Zhengzhou 450001, China
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7
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Eidhof I, Krebbers A, van de Warrenburg B, Schenck A. Ataxia-associated DNA repair genes protect the Drosophila mushroom body and locomotor function against glutamate signaling-associated damage. Front Neural Circuits 2023; 17:1148947. [PMID: 37476399 PMCID: PMC10354283 DOI: 10.3389/fncir.2023.1148947] [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: 01/20/2023] [Accepted: 06/20/2023] [Indexed: 07/22/2023] Open
Abstract
The precise control of motor movements is of fundamental importance to all behaviors in the animal kingdom. Efficient motor behavior depends on dedicated neuronal circuits - such as those in the cerebellum - that are controlled by extensive genetic programs. Autosomal recessive cerebellar ataxias (ARCAs) provide a valuable entry point into how interactions between genetic programs maintain cerebellar motor circuits. We previously identified a striking enrichment of DNA repair genes in ARCAs. How dysfunction of ARCA-associated DNA repair genes leads to preferential cerebellar dysfunction and impaired motor function is however unknown. The expression of ARCA DNA repair genes is not specific to the cerebellum. Only a limited number of animal models for DNA repair ARCAs exist, and, even for these, the interconnection between DNA repair defects, cerebellar circuit dysfunction, and motor behavior is barely established. We used Drosophila melanogaster to characterize the function of ARCA-associated DNA repair genes in the mushroom body (MB), a structure in the Drosophila central brain that shares structural features with the cerebellum. Here, we demonstrate that the MB is required for efficient startle-induced and spontaneous motor behaviors. Inhibition of synaptic transmission and loss-of-function of ARCA-associated DNA repair genes in the MB affected motor behavior in several assays. These motor deficits correlated with increased levels of MB DNA damage, MB Kenyon cell apoptosis and/or alterations in MB morphology. We further show that expression of genes involved in glutamate signaling pathways are highly, specifically, and persistently elevated in the postnatal human cerebellum. Manipulation of glutamate signaling in the MB induced motor defects, Kenyon cell DNA damage and apoptosis. Importantly, pharmacological reduction of glutamate signaling in the ARCA DNA repair models rescued the identified motor deficits, suggesting a role for aberrant glutamate signaling in ARCA-DNA repair disorders. In conclusion, our data highlight the importance of ARCA-associated DNA repair genes and glutamate signaling pathways to the cerebellum, the Drosophila MB and motor behavior. We propose that glutamate signaling may confer preferential cerebellar vulnerability in ARCA-associated DNA repair disorders. Targeting glutamate signaling could provide an exciting therapeutic entry point in this large group of so far untreatable disorders.
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Affiliation(s)
- Ilse Eidhof
- Department of Human Genetics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Alina Krebbers
- Department of Human Genetics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Bart van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
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8
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Li H, Yu Y, Zhang J, Wang Y, Zhang L, Zhai J, Zhang Y. Gut microbiota influences feeding behavior via changes in olfactory receptor gene expression in Colorado potato beetles. Front Microbiol 2023; 14:1197700. [PMID: 37455752 PMCID: PMC10338844 DOI: 10.3389/fmicb.2023.1197700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/19/2023] [Indexed: 07/18/2023] Open
Abstract
The Colorado potato beetle (CPB) is an internationally recognized plant quarantine pest that causes serious losses to potato agricultural production. The gut microbiota plays an important role in its growth and development, and the olfactory system plays an important role in insect feeding behavior. The gut microbiota is known to be capable of inducing changes in the olfactory systems of insects. However, the way these associated gut microbes influence the feeding-related behaviors of CPBs remains unclear. To explore the relationship between them, fresh potato leaves immersed in a mixture of five antibiotics (tetracycline, penicillin, ofloxacin, ciprofloxacin, and ampicillin) at specific concentrations for 1 h were fed to adult CPBs to reduce the abundance of gut microbes. We found that the feeding behavior of CPBs was significantly affected by the gut microbiota and that Pseudomonas was significantly higher in abundance in the control group than in the antibiotic group. We then used transcriptome sequencing to explore the differences in olfactory receptor genes in the heads of non-treatment and antibiotic-fed CPBs. Through Illumina Hiseq™ sequencing and screening of differential genes, we found that the olfactory receptor gene LdecOR9 was significantly upregulated and LdecOR17 was significantly downregulated after antibiotic feeding. A real-time polymerase chain reaction was used to verify the changes in olfactory receptor gene expression in the non-treatment groups and antibiotic-treated groups. The feeding behavior was partially rescued after CPBs were re-fed with intestinal bacteria. These results indicate that a certain amount of gut microbiota can result in the loss of the olfactory discrimination ability of CPBs to host plants. In summary, this study investigated the relationship between gut microbiota and olfactory genes, providing a reference for research on microbial control.
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Affiliation(s)
- Hongwei Li
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, China
- CAIQ Center for Biosafety in Sanya, Sanya, China
| | - Yanxue Yu
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, China
| | - Jian Zhang
- Technology Center of Suifenhe Customs District, Mudanjiang, China
| | | | - Liu Zhang
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, China
| | - Junfeng Zhai
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, China
| | - Yongjiang Zhang
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, China
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9
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Bonanno SL, Krantz DE. Transcriptional changes in specific subsets of Drosophila neurons following inhibition of the serotonin transporter. Transl Psychiatry 2023; 13:226. [PMID: 37355701 DOI: 10.1038/s41398-023-02521-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/06/2023] [Accepted: 06/13/2023] [Indexed: 06/26/2023] Open
Abstract
The transcriptional effects of SSRIs and other serotonergic drugs remain unclear, in part due to the heterogeneity of postsynaptic cells, which may respond differently to changes in serotonergic signaling. Relatively simple model systems such as Drosophila afford more tractable microcircuits in which to investigate these changes in specific cell types. Here, we focus on the mushroom body, an insect brain structure heavily innervated by serotonin and comprised of multiple different but related subtypes of Kenyon cells. We use fluorescence-activated cell sorting of Kenyon cells, followed by either bulk or single-cell RNA sequencing to explore the transcriptomic response of these cells to SERT inhibition. We compared the effects of two different Drosophila Serotonin Transporter (dSERT) mutant alleles as well as feeding the SSRI citalopram to adult flies. We find that the genetic architecture associated with one of the mutants contributed to significant artefactual changes in expression. Comparison of differential expression caused by loss of SERT during development versus aged, adult flies, suggests that changes in serotonergic signaling may have relatively stronger effects during development, consistent with behavioral studies in mice. Overall, our experiments revealed limited transcriptomic changes in Kenyon cells, but suggest that different subtypes may respond differently to SERT loss-of-function. Further work exploring the effects of SERT loss-of-function in other circuits may be used help to elucidate how SSRIs differentially affect a variety of different neuronal subtypes both during development and in adults.
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Affiliation(s)
- Shivan L Bonanno
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - David E Krantz
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA.
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10
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Sgammeglia N, Widmer YF, Kaldun JC, Fritsch C, Bruggmann R, Sprecher SG. Memory phase-specific genes in the Mushroom Bodies identified using CrebB-target DamID. PLoS Genet 2023; 19:e1010802. [PMID: 37307281 DOI: 10.1371/journal.pgen.1010802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 05/29/2023] [Indexed: 06/14/2023] Open
Abstract
The formation of long-term memories requires changes in the transcriptional program and de novo protein synthesis. One of the critical regulators for long-term memory (LTM) formation and maintenance is the transcription factor CREB. Genetic studies have dissected the requirement of CREB activity within memory circuits, however less is known about the genetic mechanisms acting downstream of CREB and how they may contribute defining LTM phases. To better understand the downstream mechanisms, we here used a targeted DamID approach (TaDa). We generated a CREB-Dam fusion protein using the fruit fly Drosophila melanogaster as model. Expressing CREB-Dam in the mushroom bodies (MBs), a brain center implicated in olfactory memory formation, we identified genes that are differentially expressed between paired and unpaired appetitive training paradigm. Of those genes we selected candidates for an RNAi screen in which we identified genes causing increased or decreased LTM.
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Affiliation(s)
- Noemi Sgammeglia
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Yves F Widmer
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Jenifer C Kaldun
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Cornelia Fritsch
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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11
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Bonanno SL, Krantz DE. Transcriptional changes in specific subsets of Drosophila neurons following inhibition of the serotonin transporter. RESEARCH SQUARE 2023:rs.3.rs-2626506. [PMID: 36993644 PMCID: PMC10055553 DOI: 10.21203/rs.3.rs-2626506/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The transcriptional effects of SSRIs and other serotonergic drugs remain unclear, in part due to the heterogeneity of postsynaptic cells, which may respond differently to changes in serotonergic signaling. Relatively simple model systems such as Drosophila afford more tractable microcircuits in which to investigate these changes in specific cell types. Here, we focus on the mushroom body, an insect brain structure heavily innervated by serotonin and comprised of multiple different but related subtypes of Kenyon cells. We use fluorescence activated cell sorting of Kenyon cells, followed by either or bulk or single cell RNA sequencing to explore the transcriptomic response of these cells to SERT inhibition. We compared the effects of two different Drosophila Serotonin Transporter (dSERT) mutant alleles as well as feeding the SSRI citalapram to adult flies. We find that the genetic architecture associated with one of the mutants contributed to significant artefactual changes in expression. Comparison of differential expression caused by loss of SERT during development versus aged, adult flies, suggests that changes in serotonergic signaling may have relatively stronger effects during development, consistent with behavioral studies in mice. Overall, our experiments revealed limited transcriptomic changes in Kenyon cells, but suggest that different subtypes may respond differently to SERT loss-of-function. Further work exploring the effects of SERT loss-of-function in other Drosophila circuits may be used help to elucidate how SSRIs differentially affect a variety of different neuronal subtypes both during development and in adults.
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Affiliation(s)
- Shivan L. Bonanno
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - David E. Krantz
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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12
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Palmateer CM, Artikis C, Brovero SG, Friedman B, Gresham A, Arbeitman MN. Single-cell transcriptome profiles of Drosophila fruitless-expressing neurons from both sexes. eLife 2023; 12:e78511. [PMID: 36724009 PMCID: PMC9891730 DOI: 10.7554/elife.78511] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 01/08/2023] [Indexed: 02/02/2023] Open
Abstract
Drosophila melanogaster reproductive behaviors are orchestrated by fruitless neurons. We performed single-cell RNA-sequencing on pupal neurons that produce sex-specifically spliced fru transcripts, the fru P1-expressing neurons. Uniform Manifold Approximation and Projection (UMAP) with clustering generates an atlas containing 113 clusters. While the male and female neurons overlap in UMAP space, more than half the clusters have sex differences in neuron number, and nearly all clusters display sex-differential expression. Based on an examination of enriched marker genes, we annotate clusters as circadian clock neurons, mushroom body Kenyon cell neurons, neurotransmitter- and/or neuropeptide-producing, and those that express doublesex. Marker gene analyses also show that genes that encode members of the immunoglobulin superfamily of cell adhesion molecules, transcription factors, neuropeptides, neuropeptide receptors, and Wnts have unique patterns of enriched expression across the clusters. In vivo spatial gene expression links to the clusters are examined. A functional analysis of fru P1 circadian neurons shows they have dimorphic roles in activity and period length. Given that most clusters are comprised of male and female neurons indicates that the sexes have fru P1 neurons with common gene expression programs. Sex-specific expression is overlaid on this program, to build the potential for vastly different sex-specific behaviors.
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Affiliation(s)
- Colleen M Palmateer
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Catherina Artikis
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Savannah G Brovero
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Benjamin Friedman
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Alexis Gresham
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
| | - Michelle N Arbeitman
- Department of Biomedical Sciences, Florida State University, College of MedicineTallahasseeUnited States
- Program of Neuroscience, Florida State UniversityTallahasseeUnited States
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13
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CREBB repression of protein synthesis in mushroom body gates long-term memory formation in Drosophila. Proc Natl Acad Sci U S A 2022; 119:e2211308119. [PMID: 36469774 PMCID: PMC9897441 DOI: 10.1073/pnas.2211308119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Learned experiences are not necessarily consolidated into long-term memory (LTM) unless they are periodic and meaningful. LTM depends on de novo protein synthesis mediated by cyclic AMP response element-binding protein (CREB) activity. In Drosophila, two creb genes (crebA, crebB) and multiple CREB isoforms have reported influences on aversive olfactory LTM in response to multiple cycles of spaced conditioning. How CREB isoforms regulate LTM effector genes in various neural elements of the memory circuit is unclear, especially in the mushroom body (MB), a prominent associative center in the fly brain that has been shown to participate in LTM formation. Here, we report that i) spaced training induces crebB expression in MB α-lobe neurons and ii) elevating specific CREBB isoform levels in the early α/β subpopulation of MB neurons enhances LTM formation. By contrast, learning from weak training iii) induces 5-HT1A serotonin receptor synthesis, iv) activates 5-HT1A in early α/β neurons, and v) inhibits LTM formation. vi) LTM is enhanced when this inhibitory effect is relieved by down-regulating 5-HT1A or overexpressing CREBB. Our findings show that spaced training-induced CREBB antagonizes learning-induced 5-HT1A in early α/β MB neurons to modulate LTM consolidation.
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14
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Styfhals R, Zolotarov G, Hulselmans G, Spanier KI, Poovathingal S, Elagoz AM, De Winter S, Deryckere A, Rajewsky N, Ponte G, Fiorito G, Aerts S, Seuntjens E. Cell type diversity in a developing octopus brain. Nat Commun 2022; 13:7392. [PMID: 36450803 PMCID: PMC9712504 DOI: 10.1038/s41467-022-35198-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 11/22/2022] [Indexed: 12/02/2022] Open
Abstract
Octopuses are mollusks that have evolved intricate neural systems comparable with vertebrates in terms of cell number, complexity and size. The brain cell types that control their sophisticated behavioral repertoire are still unknown. Here, we profile the cell diversity of the paralarval Octopus vulgaris brain to build a cell type atlas that comprises mostly neural cells, but also multiple glial subtypes, endothelial cells and fibroblasts. We spatially map cell types to the vertical, subesophageal and optic lobes. Investigation of cell type conservation reveals a shared gene signature between glial cells of mouse, fly and octopus. Genes related to learning and memory are enriched in vertical lobe cells, which show molecular similarities with Kenyon cells in Drosophila. We construct a cell type taxonomy revealing transcriptionally related cell types, which tend to appear in the same brain region. Together, our data sheds light on cell type diversity and evolution in the octopus brain.
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Affiliation(s)
- Ruth Styfhals
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Grygoriy Zolotarov
- Laboratory for Systems Biology of Gene Regulatory Elements, Berlin Institute for Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str. 28, 10115, Berlin, Germany
| | - Gert Hulselmans
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | - Katina I Spanier
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | | | - Ali M Elagoz
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Seppe De Winter
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | - Astrid Deryckere
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
- Department of Biological Sciences, Columbia University, New York, US
| | - Nikolaus Rajewsky
- Laboratory for Systems Biology of Gene Regulatory Elements, Berlin Institute for Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str. 28, 10115, Berlin, Germany
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Graziano Fiorito
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Stein Aerts
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | - Eve Seuntjens
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium.
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15
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Ai S, Zhang Y, Chen Y, Zhang T, Zhong G, Yi X. Insect-Microorganism Interaction Has Implicates on Insect Olfactory Systems. INSECTS 2022; 13:1094. [PMID: 36555004 PMCID: PMC9787996 DOI: 10.3390/insects13121094] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
Olfaction plays an essential role in various insect behaviors, including habitat selection, access to food, avoidance of predators, inter-species communication, aggregation, and reproduction. The olfactory process involves integrating multiple signals from external conditions and internal physiological states, including living environments, age, physiological conditions, and circadian rhythms. As microorganisms and insects form tight interactions, the behaviors of insects are constantly challenged by versatile microorganisms via olfactory cues. To better understand the microbial influences on insect behaviors via olfactory cues, this paper summarizes three different ways in which microorganisms modulate insect behaviors. Here, we deciphered three interesting aspects of microorganisms-contributed olfaction: (1) How do volatiles emitted by microorganisms affect the behaviors of insects? (2) How do microorganisms reshape the behaviors of insects by inducing changes in the synthesis of host volatiles? (3) How do symbiotic microorganisms act on insects by modulating behaviors?
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Affiliation(s)
- Shupei Ai
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Yuhua Zhang
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Yaoyao Chen
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Tong Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Guohua Zhong
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Xin Yi
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
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16
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Islam IM, Erclik T. Imp and Syp mediated temporal patterning of neural stem cells in the developing Drosophila CNS. Genetics 2022; 222:6650182. [PMID: 35881070 PMCID: PMC9434295 DOI: 10.1093/genetics/iyac103] [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: 04/21/2022] [Accepted: 06/21/2022] [Indexed: 11/12/2022] Open
Abstract
The assembly of complex neural circuits requires that stem cells generate diverse types of neurons in the correct temporal order. Pioneering work in the Drosophila embryonic ventral nerve cord has shown that neural stem cells are temporally patterned by the sequential expression of rapidly changing transcription factors to generate diversity in their progeny. In recent years, a second temporal patterning mechanism, driven by the opposing gradients of the Imp and Syp RNA-binding proteins, has emerged as a powerful way to generate neural diversity. This long-range temporal patterning mechanism is utilized in the extended neural stem cell lineages of the postembryonic fly brain. Here, we review the role played by Imp and Syp gradients in several neural stem cell lineages, focusing on how they specify sequential neural fates through the post-transcriptional regulation of target genes, including the Chinmo and Mamo transcription factors. We further discuss how upstream inputs, including hormonal signals, modify the output of these gradients to couple neurogenesis with the development of the organism. Finally, we review the roles that the Imp and Syp gradients play beyond the generation of diversity, including the regulation of stem cell proliferation, the timing of neural stem cell lineage termination, and the coupling of neuronal birth order to circuit assembly.
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Affiliation(s)
- Ishrat Maliha Islam
- Departments of Biology and Cell & Systems Biology, University of Toronto-Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Ted Erclik
- Departments of Biology and Cell & Systems Biology, University of Toronto-Mississauga, Mississauga, ON L5L 1C6, Canada
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17
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Palavicino-Maggio CB, Sengupta S. The Neuromodulatory Basis of Aggression: Lessons From the Humble Fruit Fly. Front Behav Neurosci 2022; 16:836666. [PMID: 35517573 PMCID: PMC9062135 DOI: 10.3389/fnbeh.2022.836666] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/07/2022] [Indexed: 11/22/2022] Open
Abstract
Aggression is an intrinsic trait that organisms of almost all species, humans included, use to get access to food, shelter, and mating partners. To maximize fitness in the wild, an organism must vary the intensity of aggression toward the same or different stimuli. How much of this variation is genetic and how much is externally induced, is largely unknown but is likely to be a combination of both. Irrespective of the source, one of the principal physiological mechanisms altering the aggression intensity involves neuromodulation. Any change or variation in aggression intensity is most likely governed by a complex interaction of several neuromodulators acting via a meshwork of neural circuits. Resolving aggression-specific neural circuits in a mammalian model has proven challenging due to the highly complex nature of the mammalian brain. In that regard, the fruit fly model Drosophila melanogaster has provided insights into the circuit-driven mechanisms of aggression regulation and its underlying neuromodulatory basis. Despite morphological dissimilarities, the fly brain shares striking similarities with the mammalian brain in genes, neuromodulatory systems, and circuit-organization, making the findings from the fly model extremely valuable for understanding the fundamental circuit logic of human aggression. This review discusses our current understanding of how neuromodulators regulate aggression based on findings from the fruit fly model. We specifically focus on the roles of Serotonin (5-HT), Dopamine (DA), Octopamine (OA), Acetylcholine (ACTH), Sex Peptides (SP), Tachykinin (TK), Neuropeptide F (NPF), and Drosulfakinin (Dsk) in fruit fly male and female aggression.
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Affiliation(s)
- Caroline B Palavicino-Maggio
- Basic Neuroscience Division, Department of Psychiatry, Harvard Medical School, McLean Hospital, Boston, MA, United States.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Saheli Sengupta
- Basic Neuroscience Division, Department of Psychiatry, Harvard Medical School, McLean Hospital, Boston, MA, United States
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18
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Torres-Méndez A, Pop S, Bonnal S, Almudi I, Avola A, Roberts RJV, Paolantoni C, Alcaina-Caro A, Martín-Anduaga A, Haussmann IU, Morin V, Casares F, Soller M, Kadener S, Roignant JY, Prieto-Godino L, Irimia M. Parallel evolution of a splicing program controlling neuronal excitability in flies and mammals. SCIENCE ADVANCES 2022; 8:eabk0445. [PMID: 35089784 PMCID: PMC8797185 DOI: 10.1126/sciadv.abk0445] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/08/2021] [Indexed: 05/08/2023]
Abstract
Alternative splicing increases neuronal transcriptomic complexity throughout animal phylogeny. To delve into the mechanisms controlling the assembly and evolution of this regulatory layer, we characterized the neuronal microexon program in Drosophila and compared it with that of mammals. In nonvertebrate bilaterians, this splicing program is restricted to neurons by the posttranscriptional processing of the enhancer of microexons (eMIC) domain in Srrm234. In Drosophila, this processing is dependent on regulation by Elav/Fne. eMIC deficiency or misexpression leads to widespread neurological alterations largely emerging from impaired neuronal activity, as revealed by a combination of neuronal imaging experiments and cell type-specific rescues. These defects are associated with the genome-wide skipping of short neural exons, which are strongly enriched in ion channels. We found no overlap of eMIC-regulated exons between flies and mice, illustrating how ancient posttranscriptional programs can evolve independently in different phyla to affect distinct cellular modules while maintaining cell-type specificity.
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Affiliation(s)
- Antonio Torres-Méndez
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona 08003, Spain
- Francis Crick Institute, London, UK
| | | | - Sophie Bonnal
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona 08003, Spain
| | - Isabel Almudi
- Centro Andaluz de Biología del Desarrollo (CABD), CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
- Department of Genetics, Microbiology and Statistics and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | | | | | - Chiara Paolantoni
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Ana Alcaina-Caro
- Centro Andaluz de Biología del Desarrollo (CABD), CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
| | | | - Irmgard U. Haussmann
- Department of Life Science, School of Health Sciences, Birmingham City University, Birmingham B5 3TN, UK
| | - Violeta Morin
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Fernando Casares
- Centro Andaluz de Biología del Desarrollo (CABD), CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
| | - Matthias Soller
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- Birmingham Centre for Genome Biology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | | | - Jean-Yves Roignant
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | | | - Manuel Irimia
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08003, Spain
- ICREA, Barcelona, Spain
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19
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Janssens J, Aibar S, Taskiran II, Ismail JN, Gomez AE, Aughey G, Spanier KI, De Rop FV, González-Blas CB, Dionne M, Grimes K, Quan XJ, Papasokrati D, Hulselmans G, Makhzami S, De Waegeneer M, Christiaens V, Southall T, Aerts S. Decoding gene regulation in the fly brain. Nature 2022; 601:630-636. [PMID: 34987221 DOI: 10.1038/s41586-021-04262-z] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 11/17/2021] [Indexed: 12/13/2022]
Abstract
The Drosophila brain is a frequently used model in neuroscience. Single-cell transcriptome analysis1-6, three-dimensional morphological classification7 and electron microscopy mapping of the connectome8,9 have revealed an immense diversity of neuronal and glial cell types that underlie an array of functional and behavioural traits in the fly. The identities of these cell types are controlled by gene regulatory networks (GRNs), involving combinations of transcription factors that bind to genomic enhancers to regulate their target genes. Here, to characterize GRNs at the cell-type level in the fly brain, we profiled the chromatin accessibility of 240,919 single cells spanning 9 developmental timepoints and integrated these data with single-cell transcriptomes. We identify more than 95,000 regulatory regions that are used in different neuronal cell types, of which 70,000 are linked to developmental trajectories involving neurogenesis, reprogramming and maturation. For 40 cell types, uniquely accessible regions were associated with their expressed transcription factors and downstream target genes through a combination of motif discovery, network inference and deep learning, creating enhancer GRNs. The enhancer architectures revealed by DeepFlyBrain lead to a better understanding of neuronal regulatory diversity and can be used to design genetic driver lines for cell types at specific timepoints, facilitating their characterization and manipulation.
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Affiliation(s)
- Jasper Janssens
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Sara Aibar
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Ibrahim Ihsan Taskiran
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Joy N Ismail
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | | | - Gabriel Aughey
- Department of Life Sciences, Imperial College London, London, UK
| | - Katina I Spanier
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Florian V De Rop
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Carmen Bravo González-Blas
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Marc Dionne
- Department of Life Sciences, Imperial College London, London, UK
| | - Krista Grimes
- Department of Life Sciences, Imperial College London, London, UK
| | - Xiao Jiang Quan
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Dafni Papasokrati
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Gert Hulselmans
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Samira Makhzami
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Maxime De Waegeneer
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Valerie Christiaens
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Tony Southall
- Department of Life Sciences, Imperial College London, London, UK
| | - Stein Aerts
- VIB Center for Brain & Disease Research, Leuven, Belgium. .,Department of Human Genetics, KU Leuven, Leuven, Belgium.
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20
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Li Q, Jang H, Lim KY, Lessing A, Stavropoulos N. insomniac links the development and function of a sleep-regulatory circuit. eLife 2021; 10:65437. [PMID: 34908527 PMCID: PMC8758140 DOI: 10.7554/elife.65437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
Although many genes are known to influence sleep, when and how they impact sleep-regulatory circuits remain ill-defined. Here, we show that insomniac (inc), a conserved adaptor for the autism-associated Cul3 ubiquitin ligase, acts in a restricted period of neuronal development to impact sleep in adult Drosophila. The loss of inc causes structural and functional alterations within the mushroom body (MB), a center for sensory integration, associative learning, and sleep regulation. In inc mutants, MB neurons are produced in excess, develop anatomical defects that impede circuit assembly, and are unable to promote sleep when activated in adulthood. Our findings link neurogenesis and postmitotic development of sleep-regulatory neurons to their adult function and suggest that developmental perturbations of circuits that couple sensory inputs and sleep may underlie sleep dysfunction in neurodevelopmental disorders.
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Affiliation(s)
- Qiuling Li
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Hyunsoo Jang
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Kayla Y Lim
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Alexie Lessing
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Nicholas Stavropoulos
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
- Waksman Institute, Rutgers UniversityPiscatawayUnited States
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21
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Rosenthal JS, Yuan Q. Constructing and Tuning Excitatory Cholinergic Synapses: The Multifaceted Functions of Nicotinic Acetylcholine Receptors in Drosophila Neural Development and Physiology. Front Cell Neurosci 2021; 15:720560. [PMID: 34650404 PMCID: PMC8505678 DOI: 10.3389/fncel.2021.720560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAchRs) are widely distributed within the nervous system across most animal species. Besides their well-established roles in mammalian neuromuscular junctions, studies using invertebrate models have also proven fruitful in revealing the function of nAchRs in the central nervous system. During the earlier years, both in vitro and animal studies had helped clarify the basic molecular features of the members of the Drosophila nAchR gene family and illustrated their utility as targets for insecticides. Later, increasingly sophisticated techniques have illuminated how nAchRs mediate excitatory neurotransmission in the Drosophila brain and play an integral part in neural development and synaptic plasticity, as well as cognitive processes such as learning and memory. This review is intended to provide an updated survey of Drosophila nAchR subunits, focusing on their molecular diversity and unique contributions to physiology and plasticity of the fly neural circuitry. We will also highlight promising new avenues for nAchR research that will likely contribute to better understanding of central cholinergic neurotransmission in both Drosophila and other organisms.
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Affiliation(s)
- Justin S Rosenthal
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Quan Yuan
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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22
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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: 15] [Impact Index Per Article: 5.0] [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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23
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Allen AM, B Sokolowski M. Expression of the foraging gene in adult Drosophila melanogaster. J Neurogenet 2021; 35:192-212. [PMID: 34382904 PMCID: PMC8846931 DOI: 10.1080/01677063.2021.1941946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The foraging gene in Drosophila melanogaster, which encodes a cGMP-dependent protein kinase, is a highly conserved, complex gene with multiple pleiotropic behavioral and physiological functions in both the larval and adult fly. Adult foraging expression is less well characterized than in the larva. We characterized foraging expression in the brain, gastric system, and reproductive systems using a T2A-Gal4 gene-trap allele. In the brain, foraging expression appears to be restricted to multiple sub-types of glia. This glial-specific cellular localization of foraging was supported by single-cell transcriptomic atlases of the adult brain. foraging is extensively expressed in most cell types in the gastric and reproductive systems. We then mapped multiple cis-regulatory elements responsible for parts of the observed expression patterns by a nested cloned promoter-Gal4 analysis. The mapped cis-regulatory elements were consistently modular when comparing the larval and adult expression patterns. These new data using the T2A-Gal4 gene-trap and cloned foraging promoter fusion GAL4's are discussed with respect to previous work using an anti-FOR antibody, which we show here to be non-specific. Future studies of foraging's function will consider roles for glial subtypes and peripheral tissues (gastric and reproductive systems) in foraging's pleiotropic behavioral and physiological effects.
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Affiliation(s)
- Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Marla B Sokolowski
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
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24
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Ryvkin J, Bentzur A, Shmueli A, Tannenbaum M, Shallom O, Dokarker S, Benichou JIC, Levi M, Shohat-Ophir G. Transcriptome Analysis of NPFR Neurons Reveals a Connection Between Proteome Diversity and Social Behavior. Front Behav Neurosci 2021; 15:628662. [PMID: 33867948 PMCID: PMC8044454 DOI: 10.3389/fnbeh.2021.628662] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/16/2021] [Indexed: 12/26/2022] Open
Abstract
Social behaviors are mediated by the activity of highly complex neuronal networks, the function of which is shaped by their transcriptomic and proteomic content. Contemporary advances in neurogenetics, genomics, and tools for automated behavior analysis make it possible to functionally connect the transcriptome profile of candidate neurons to their role in regulating behavior. In this study we used Drosophila melanogaster to explore the molecular signature of neurons expressing receptor for neuropeptide F (NPF), the fly homolog of neuropeptide Y (NPY). By comparing the transcription profile of NPFR neurons to those of nine other populations of neurons, we discovered that NPFR neurons exhibit a unique transcriptome, enriched with receptors for various neuropeptides and neuromodulators, as well as with genes known to regulate behavioral processes, such as learning and memory. By manipulating RNA editing and protein ubiquitination programs specifically in NPFR neurons, we demonstrate that the proper expression of their unique transcriptome and proteome is required to suppress male courtship and certain features of social group interaction. Our results highlight the importance of transcriptome and proteome diversity in the regulation of complex behaviors and pave the path for future dissection of the spatiotemporal regulation of genes within highly complex tissues, such as the brain.
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Affiliation(s)
- Julia Ryvkin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Assa Bentzur
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Anat Shmueli
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Miriam Tannenbaum
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Omri Shallom
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Shiran Dokarker
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Jennifer I. C. Benichou
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Mali Levi
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Galit Shohat-Ophir
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel
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25
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Roselli C, Ramaswami M, Boto T, Cervantes-Sandoval I. The Making of Long-Lasting Memories: A Fruit Fly Perspective. Front Behav Neurosci 2021; 15:662129. [PMID: 33859556 PMCID: PMC8042140 DOI: 10.3389/fnbeh.2021.662129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/08/2021] [Indexed: 11/25/2022] Open
Abstract
Understanding the nature of the molecular mechanisms underlying memory formation, consolidation, and forgetting are some of the fascinating questions in modern neuroscience. The encoding, stabilization and elimination of memories, rely on the structural reorganization of synapses. These changes will enable the facilitation or depression of neural activity in response to the acquisition of new information. In other words, these changes affect the weight of specific nodes within a neural network. We know that these plastic reorganizations require de novo protein synthesis in the context of Long-term memory (LTM). This process depends on neural activity triggered by the learned experience. The use of model organisms like Drosophila melanogaster has been proven essential for advancing our knowledge in the field of neuroscience. Flies offer an optimal combination of a more straightforward nervous system, composed of a limited number of cells, and while still displaying complex behaviors. Studies in Drosophila neuroscience, which expanded over several decades, have been critical for understanding the cellular and molecular mechanisms leading to the synaptic and behavioral plasticity occurring in the context of learning and memory. This is possible thanks to sophisticated technical approaches that enable precise control of gene expression in the fruit fly as well as neural manipulation, like chemogenetics, thermogenetics, or optogenetics. The search for the identity of genes expressed as a result of memory acquisition has been an active interest since the origins of behavioral genetics. From screenings of more or less specific candidates to broader studies based on transcriptome analysis, our understanding of the genetic control behind LTM has expanded exponentially in the past years. Here we review recent literature regarding how the formation of memories induces a rapid, extensive and, in many cases, transient wave of transcriptional activity. After a consolidation period, transcriptome changes seem more stable and likely represent the synthesis of new proteins. The complexity of the circuitry involved in memory formation and consolidation is such that there are localized changes in neural activity, both regarding temporal dynamics and the nature of neurons and subcellular locations affected, hence inducing specific temporal and localized changes in protein expression. Different types of neurons are recruited at different times into memory traces. In LTM, the synthesis of new proteins is required in specific subsets of cells. This de novo translation can take place in the somatic cytoplasm and/or locally in distinct zones of compartmentalized synaptic activity, depending on the nature of the proteins and the plasticity-inducing processes that occur. We will also review recent advances in understanding how localized changes are confined to the relevant synapse. These recent studies have led to exciting discoveries regarding proteins that were not previously involved in learning and memory processes. This invaluable information will lead to future functional studies on the roles that hundreds of new molecular actors play in modulating neural activity.
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Affiliation(s)
- Camilla Roselli
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Mani Ramaswami
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland.,National Centre for Biological Sciences, TIFR, Bengaluru, India
| | - Tamara Boto
- Trinity College Institute of Neuroscience, Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Isaac Cervantes-Sandoval
- Department of Biology, Georgetown University, Washington, DC, United States.,Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States
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26
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Chvilicek MM, Titos I, Rothenfluh A. The Neurotransmitters Involved in Drosophila Alcohol-Induced Behaviors. Front Behav Neurosci 2020; 14:607700. [PMID: 33384590 PMCID: PMC7770116 DOI: 10.3389/fnbeh.2020.607700] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Alcohol is a widely used and abused substance with numerous negative consequences for human health and safety. Historically, alcohol's widespread, non-specific neurobiological effects have made it a challenge to study in humans. Therefore, model organisms are a critical tool for unraveling the mechanisms of alcohol action and subsequent effects on behavior. Drosophila melanogaster is genetically tractable and displays a vast behavioral repertoire, making it a particularly good candidate for examining the neurobiology of alcohol responses. In addition to being experimentally amenable, Drosophila have high face and mechanistic validity: their alcohol-related behaviors are remarkably consistent with humans and other mammalian species, and they share numerous conserved neurotransmitters and signaling pathways. Flies have a long history in alcohol research, which has been enhanced in recent years by the development of tools that allow for manipulating individual Drosophila neurotransmitters. Through advancements such as the GAL4/UAS system and CRISPR/Cas9 mutagenesis, investigation of specific neurotransmitters in small subsets of neurons has become ever more achievable. In this review, we describe recent progress in understanding the contribution of seven neurotransmitters to fly behavior, focusing on their roles in alcohol response: dopamine, octopamine, tyramine, serotonin, glutamate, GABA, and acetylcholine. We chose these small-molecule neurotransmitters due to their conservation in mammals and their importance for behavior. While neurotransmitters like dopamine and octopamine have received significant research emphasis regarding their contributions to behavior, others, like glutamate, GABA, and acetylcholine, remain relatively unexplored. Here, we summarize recent genetic and behavioral findings concerning these seven neurotransmitters and their roles in the behavioral response to alcohol, highlighting the fitness of the fly as a model for human alcohol use.
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Affiliation(s)
- Maggie M. Chvilicek
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
| | - Iris Titos
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
| | - Adrian Rothenfluh
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, United States
- Department of Human Genetics, University of Utah, Salt Lake City, UT, United States
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27
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Mechanisms underlying homeostatic plasticity in the Drosophila mushroom body in vivo. Proc Natl Acad Sci U S A 2020; 117:16606-16615. [PMID: 32601210 DOI: 10.1073/pnas.1921294117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Neural network function requires an appropriate balance of excitation and inhibition to be maintained by homeostatic plasticity. However, little is known about homeostatic mechanisms in the intact central brain in vivo. Here, we study homeostatic plasticity in the Drosophila mushroom body, where Kenyon cells receive feedforward excitation from olfactory projection neurons and feedback inhibition from the anterior paired lateral neuron (APL). We show that prolonged (4-d) artificial activation of the inhibitory APL causes increased Kenyon cell odor responses after the artificial inhibition is removed, suggesting that the mushroom body compensates for excess inhibition. In contrast, there is little compensation for lack of inhibition (blockade of APL). The compensation occurs through a combination of increased excitation of Kenyon cells and decreased activation of APL, with differing relative contributions for different Kenyon cell subtypes. Our findings establish the fly mushroom body as a model for homeostatic plasticity in vivo.
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28
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Rossi AM, Desplan C. Extrinsic activin signaling cooperates with an intrinsic temporal program to increase mushroom body neuronal diversity. eLife 2020; 9:58880. [PMID: 32628110 PMCID: PMC7365662 DOI: 10.7554/elife.58880] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/03/2020] [Indexed: 12/16/2022] Open
Abstract
Temporal patterning of neural progenitors leads to the sequential production of diverse neurons. To understand how extrinsic cues influence intrinsic temporal programs, we studied Drosophila mushroom body progenitors (neuroblasts) that sequentially produce only three neuronal types: γ, then α’β’, followed by αβ. Opposing gradients of two RNA-binding proteins Imp and Syp comprise the intrinsic temporal program. Extrinsic activin signaling regulates the production of α’β’ neurons but whether it affects the intrinsic temporal program was not known. We show that the activin ligand Myoglianin from glia regulates the temporal factor Imp in mushroom body neuroblasts. Neuroblasts missing the activin receptor Baboon have a delayed intrinsic program as Imp is higher than normal during the α’β’ temporal window, causing the loss of α’β’ neurons, a decrease in αβ neurons, and a likely increase in γ neurons, without affecting the overall number of neurons produced. Our results illustrate that an extrinsic cue modifies an intrinsic temporal program to increase neuronal diversity.
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Affiliation(s)
- Anthony M Rossi
- Department of Biology, New York University, New York, United States
| | - Claude Desplan
- Department of Biology, New York University, New York, United States
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29
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Petruccelli E, Brown T, Waterman A, Ledru N, Kaun KR. Alcohol Causes Lasting Differential Transcription in Drosophila Mushroom Body Neurons. Genetics 2020; 215:103-116. [PMID: 32132098 PMCID: PMC7198272 DOI: 10.1534/genetics.120.303101] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 02/26/2020] [Indexed: 12/12/2022] Open
Abstract
Repeated alcohol experiences can produce long-lasting memories for sensory cues associated with intoxication. These memories can problematically trigger relapse in individuals recovering from alcohol use disorder (AUD). The molecular mechanisms by which ethanol changes memories to become long-lasting and inflexible remain unclear. New methods to analyze gene expression within precise neuronal cell types can provide further insight toward AUD prevention and treatment. Here, we used genetic tools in Drosophila melanogaster to investigate the lasting consequences of ethanol on transcription in memory-encoding neurons. Drosophila rely on mushroom body (MB) neurons to make associative memories, including memories of ethanol-associated sensory cues. Differential expression analyses revealed that distinct transcripts, but not genes, in the MB were associated with experiencing ethanol alone compared to forming a memory of an odor cue associated with ethanol. Adult MB-specific knockdown of spliceosome-associated proteins demonstrated the necessity of RNA-processing in ethanol memory formation. These findings highlight the dynamic, context-specific regulation of transcription in cue-encoding neurons, and the lasting effect of ethanol on transcript usage during memory formation.
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Affiliation(s)
- Emily Petruccelli
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912
- Department of Biological Sciences, Southern Illinois University Edwardsville, Illinois 62026
| | - Tariq Brown
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912
| | - Amanda Waterman
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912
| | - Nicolas Ledru
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912
| | - Karla R Kaun
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912
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30
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Allen AM, Neville MC, Birtles S, Croset V, Treiber CD, Waddell S, Goodwin SF. A single-cell transcriptomic atlas of the adult Drosophila ventral nerve cord. eLife 2020; 9:e54074. [PMID: 32314735 PMCID: PMC7173974 DOI: 10.7554/elife.54074] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/03/2020] [Indexed: 02/07/2023] Open
Abstract
The Drosophila ventral nerve cord (VNC) receives and processes descending signals from the brain to produce a variety of coordinated locomotor outputs. It also integrates sensory information from the periphery and sends ascending signals to the brain. We used single-cell transcriptomics to generate an unbiased classification of cellular diversity in the VNC of five-day old adult flies. We produced an atlas of 26,000 high-quality cells, representing more than 100 transcriptionally distinct cell types. The predominant gene signatures defining neuronal cell types reflect shared developmental histories based on the neuroblast from which cells were derived, as well as their birth order. The relative position of cells along the anterior-posterior axis could also be assigned using adult Hox gene expression. This single-cell transcriptional atlas of the adult fly VNC will be a valuable resource for future studies of neurodevelopment and behavior.
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Affiliation(s)
- Aaron M Allen
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Megan C Neville
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Sebastian Birtles
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Vincent Croset
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | | | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Stephen F Goodwin
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
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31
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Drosophila Middle-Term Memory: Amnesiac is Required for PKA Activation in the Mushroom Bodies, a Function Modulated by Neprilysin 1. J Neurosci 2020; 40:4219-4229. [PMID: 32303647 DOI: 10.1523/jneurosci.2311-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 03/30/2020] [Accepted: 04/05/2020] [Indexed: 11/21/2022] Open
Abstract
In Drosophila, the mushroom bodies (MB) constitute the central brain structure for olfactory associative memory. As in mammals, the cAMP/PKA pathway plays a key role in memory formation. In the MB, Rutabaga (Rut) adenylate cyclase acts as a coincidence detector during associative conditioning to integrate calcium influx resulting from acetylcholine stimulation and G-protein activation resulting from dopaminergic stimulation. Amnesiac encodes a secreted neuropeptide required in the MB for two phases of aversive olfactory memory. Previous sequence analysis has revealed strong homology with the mammalian pituitary adenylate cyclase-activating peptide (PACAP). Here, we examined whether amnesiac is involved in cAMP/PKA dynamics in response to dopamine and acetylcholine co-stimulation in living flies. Experiments were conducted with both sexes, or with either sex. Our data show that amnesiac is necessary for the PKA activation process that results from coincidence detection in the MB. Since PACAP peptide is cleaved by the human membrane neprilysin hNEP, we searched for an interaction between Amnesiac and Neprilysin 1 (Nep1), a fly neprilysin involved in memory. We show that when Nep1 expression is acutely knocked down in adult MB, memory deficits displayed by amn hypomorphic mutants are rescued. Consistently, Nep1 inhibition also restores normal PKA activation in amn mutant flies. Taken together, the results suggest that Nep1 targets Amnesiac degradation to terminate its signaling function. Our work thus highlights a key role for Amnesiac in establishing within the MB the PKA dynamics that sustain middle-term memory (MTM) formation, a function modulated by Nep1.SIGNIFICANCE STATEMENT The Drosophila amnesiac gene encodes a secreted neuropeptide whose expression is required for specific memory phases in the mushroom bodies (MB), the olfactory memory center. Here, we show that Amnesiac is required for PKA activation resulting from coincidence detection, a mechanism by which the MB integrate two spatially distinct stimuli to encode associative memory. Furthermore, our results uncover a functional relationship between Amnesiac and Neprilysin 1 (Nep1), a membrane peptidase involved in memory and expressed in the MB. These results suggest that Nep1 modulates Amnesiac levels. We propose that on conditioning, Amnesiac release from the MB allows, via an autocrine process, the sustaining of PKA activation-mediating memory, which subsequently is inactivated by Nep1 degradation.
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32
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Concerted Actions of Octopamine and Dopamine Receptors Drive Olfactory Learning. J Neurosci 2020; 40:4240-4250. [PMID: 32277043 DOI: 10.1523/jneurosci.1756-19.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 03/12/2020] [Accepted: 03/29/2020] [Indexed: 11/21/2022] Open
Abstract
Aminergic signaling modulates associative learning and memory. Substantial advance has been made in Drosophila on the dopamine receptors and circuits mediating olfactory learning; however, our knowledge of other aminergic modulation lags behind. To address this knowledge gap, we investigated the role of octopamine in olfactory conditioning. Here, we report that octopamine activity through the β-adrenergic-like receptor Octβ1R drives aversive and appetitive learning: Octβ1R in the mushroom body αβ neurons processes aversive learning, whereas Octβ1R in the projection neurons mediates appetitive learning. Our genetic interaction and imaging studies pinpoint cAMP signaling as a key downstream effector for Octβ1R function. The rutabaga-adenylyl cyclase synthesizes cAMP in a Ca2+/calmodulin-dependent manner, serving as a coincidence detector for associative learning and likely representing a downstream target for Octβ1R. Supporting this notion, the double heterozygous rutabaga/+;octβ1r/+ flies perform poorly in both aversive and appetitive conditioning, while individual heterozygous rutabaga/+ and octβ1r/+ flies behave like the wild-type control. Consistently, the mushroom body and projection neurons in the octβ1r brain exhibit blunted responses to octopamine when cAMP levels are monitored through the cAMP sensor. We previously demonstrated the pivotal functions of the D1 receptor dDA1 in aversive and appetitive learning, and the α1 adrenergic-like receptor OAMB in appetitive learning. As expected, octβ1r genetically interacts with dumb (dDA1 mutant) in aversive and appetitive learning, but it interacts with oamb only in appetitive learning. This study uncovers the indispensable contributions of dopamine and octopamine signaling to aversive and appetitive learning. All experiments were performed on mixed sex unless otherwise noted.SIGNIFICANCE STATEMENT Animals make flexible behavioral choices that are constantly shaped by experience. This plasticity is vital for animals to appropriately respond to the cues predicting benefit or harm. In Drosophila, dopamine is known to mediate both reward-based and punishment-based learning while octopamine function is important only for reward. Here, we demonstrate that the octopamine-Octβ1R-cAMP pathway processes both aversive and appetitive learning in distinct neural sites of the olfactory circuit. Furthermore, we show that the octopamine-Octβ1R and dopamine-dDA1 signals together drive both aversive and appetitive learning, whereas the octopamine-Octβ1R and octopamine-OAMB pathways jointly facilitate appetitive, but not aversive, learning. This study identifies the cognate actions of octopamine and dopamine signaling as a key neural mechanism for associative learning.
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33
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Boto T, Stahl A, Tomchik SM. Cellular and circuit mechanisms of olfactory associative learning in Drosophila. J Neurogenet 2020; 34:36-46. [PMID: 32043414 DOI: 10.1080/01677063.2020.1715971] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent years have witnessed significant progress in understanding how memories are encoded, from the molecular to the cellular and the circuit/systems levels. With a good compromise between brain complexity and behavioral sophistication, the fruit fly Drosophila melanogaster is one of the preeminent animal models of learning and memory. Here we review how memories are encoded in Drosophila, with a focus on short-term memory and an eye toward future directions. Forward genetic screens have revealed a large number of genes and transcripts necessary for learning and memory, some acting cell-autonomously. Further, the relative numerical simplicity of the fly brain has enabled the reverse engineering of learning circuits with remarkable precision, in some cases ascribing behavioral phenotypes to single neurons. Functional imaging and physiological studies have localized and parsed the plasticity that occurs during learning at some of the major loci. Connectomics projects are significantly expanding anatomical knowledge of the nervous system, filling out the roadmap for ongoing functional/physiological and behavioral studies, which are being accelerated by simultaneous tool development. These developments have provided unprecedented insight into the fundamental neural principles of learning, and lay the groundwork for deep understanding in the near future.
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Affiliation(s)
- Tamara Boto
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
| | - Aaron Stahl
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
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34
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Ras acts as a molecular switch between two forms of consolidated memory in Drosophila. Proc Natl Acad Sci U S A 2020; 117:2133-2139. [PMID: 31932418 DOI: 10.1073/pnas.1819925117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Long-lasting, consolidated memories require not only positive biological processes that facilitate long-term memories (LTM) but also the suppression of inhibitory processes that prevent them. The mushroom body neurons (MBn) in Drosophila melanogaster store protein synthesis-dependent LTM (PSD-LTM) as well as protein synthesis-independent, anesthesia-resistant memory (ARM). The formation of ARM inhibits PSD-LTM but the underlying molecular processes that mediate this interaction remain unknown. Here, we demonstrate that the Ras→Raf→rho kinase (ROCK) pathway in MBn suppresses ARM consolidation, allowing the formation of PSD-LTM. Our initial results revealed that the effects of Ras on memory are due to postacquisition processes. Ras knockdown enhanced memory expression but had no effect on acquisition. Additionally, increasing Ras activity optogenetically after, but not before, acquisition impaired memory performance. The elevated memory produced by Ras knockdown is a result of increased ARM. While Ras knockdown enhanced the consolidation of ARM, it eliminated PSD-LTM. We found that these effects are mediated by the downstream kinase Raf. Similar to Ras, knockdown of Raf enhanced ARM consolidation and impaired PSD-LTM. Surprisingly, knockdown of the canonical downstream extracellular signal-regulated kinase did not reproduce the phenotypes observed with Ras and Raf knockdown. Rather, Ras/Raf inhibition of ROCK was found to be responsible for suppressing ARM. Constitutively active ROCK enhanced ARM and impaired PSD-LTM, while decreasing ROCK activity rescued the enhanced ARM produced by Ras knockdown. We conclude that MBn Ras/Raf inhibition of ROCK suppresses the consolidation of ARM, which permits the formation of PSD-LTM.
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35
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Bielopolski N, Amin H, Apostolopoulou AA, Rozenfeld E, Lerner H, Huetteroth W, Lin AC, Parnas M. Inhibitory muscarinic acetylcholine receptors enhance aversive olfactory learning in adult Drosophila. eLife 2019; 8:48264. [PMID: 31215865 PMCID: PMC6641838 DOI: 10.7554/elife.48264] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 06/18/2019] [Indexed: 11/13/2022] Open
Abstract
Olfactory associative learning in Drosophila is mediated by synaptic plasticity between the Kenyon cells of the mushroom body and their output neurons. Both Kenyon cells and their inputs from projection neurons are cholinergic, yet little is known about the physiological function of muscarinic acetylcholine receptors in learning in adult flies. Here, we show that aversive olfactory learning in adult flies requires type A muscarinic acetylcholine receptors (mAChR-A), particularly in the gamma subtype of Kenyon cells. mAChR-A inhibits odor responses and is localized in Kenyon cell dendrites. Moreover, mAChR-A knockdown impairs the learning-associated depression of odor responses in a mushroom body output neuron. Our results suggest that mAChR-A function in Kenyon cell dendrites is required for synaptic plasticity between Kenyon cells and their output neurons.
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Affiliation(s)
- Noa Bielopolski
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hoger Amin
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | | | - Eyal Rozenfeld
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hadas Lerner
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Wolf Huetteroth
- Institute for Biology, University of Leipzig, Leipzig, Germany
| | - Andrew C Lin
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Moshe Parnas
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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