1
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Botero V, Tomchik SM. Unraveling neuronal and metabolic alterations in neurofibromatosis type 1. J Neurodev Disord 2024; 16:49. [PMID: 39217323 PMCID: PMC11365184 DOI: 10.1186/s11689-024-09565-6] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 08/02/2024] [Indexed: 09/04/2024] Open
Abstract
Neurofibromatosis type 1 (OMIM 162200) affects ~ 1 in 3,000 individuals worldwide and is one of the most common monogenetic neurogenetic disorders that impacts brain function. The disorder affects various organ systems, including the central nervous system, resulting in a spectrum of clinical manifestations. Significant progress has been made in understanding the disorder's pathophysiology, yet gaps persist in understanding how the complex signaling and systemic interactions affect the disorder. Two features of the disorder are alterations in neuronal function and metabolism, and emerging evidence suggests a potential relationship between them. This review summarizes neurofibromatosis type 1 features and recent research findings on disease mechanisms, with an emphasis on neuronal and metabolic features.
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Affiliation(s)
- Valentina Botero
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
- Department of Neuroscience, Scripps Research, Scripps Florida, Jupiter, FL, USA
- Skaggs School of Chemical and Biological Sciences, Scripps Research, La Jolla, CA, USA
| | - Seth M Tomchik
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA.
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA.
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA.
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, 52242, USA.
- Hawk-IDDRC, University of Iowa, Iowa City, IA, 52242, USA.
- Department of Neuroscience, Scripps Research, Scripps Florida, Jupiter, FL, USA.
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2
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Suarez GO, Kumar DS, Brunner H, Emel J, Teel J, Knauss A, Botero V, Broyles CN, Stahl A, Bidaye SS, Tomchik SM. Neurofibromin deficiency alters the patterning and prioritization of motor behaviors in a state-dependent manner. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.08.607070. [PMID: 39149363 PMCID: PMC11326213 DOI: 10.1101/2024.08.08.607070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Genetic disorders such as neurofibromatosis type 1 increase vulnerability to cognitive and behavioral disorders, such as autism spectrum disorder and attention-deficit/hyperactivity disorder. Neurofibromatosis type 1 results from loss-of-function mutations in the neurofibromin gene and subsequent reduction in the neurofibromin protein (Nf1). While the mechanisms have yet to be fully elucidated, loss of Nf1 may alter neuronal circuit activity leading to changes in behavior and susceptibility to cognitive and behavioral comorbidities. Here we show that mutations decreasing Nf1 expression alter motor behaviors, impacting the patterning, prioritization, and behavioral state dependence in a Drosophila model of neurofibromatosis type 1. Loss of Nf1 increases spontaneous grooming in a nonlinear spatial and temporal pattern, differentially increasing grooming of certain body parts, including the abdomen, head, and wings. This increase in grooming could be overridden by hunger in food-deprived foraging animals, demonstrating that the Nf1 effect is plastic and internal state-dependent. Stimulus-evoked grooming patterns were altered as well, with nf1 mutants exhibiting reductions in wing grooming when coated with dust, suggesting that hierarchical recruitment of grooming command circuits was altered. Yet loss of Nf1 in sensory neurons and/or grooming command neurons did not alter grooming frequency, suggesting that Nf1 affects grooming via higher-order circuit alterations. Changes in grooming coincided with alterations in walking. Flies lacking Nf1 walked with increased forward velocity on a spherical treadmill, yet there was no detectable change in leg kinematics or gait. Thus, loss of Nf1 alters motor function without affecting overall motor coordination, in contrast to other genetic disorders that impair coordination. Overall, these results demonstrate that loss of Nf1 alters the patterning and prioritization of repetitive behaviors, in a state-dependent manner, without affecting motor coordination.
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Affiliation(s)
- Genesis Omana Suarez
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
- H.L. Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Divya S. Kumar
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Hannah Brunner
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Jalen Emel
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Jensen Teel
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Anneke Knauss
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Valentina Botero
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Connor N. Broyles
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Aaron Stahl
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Salil S. Bidaye
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Seth M. Tomchik
- Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- H.L. Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
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3
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Valencia ML, Sofela FA, Jongens TA, Sehgal A. Do metabolic deficits contribute to sleep disruption in monogenic intellectual disability syndromes? Trends Neurosci 2024; 47:583-592. [PMID: 39054162 DOI: 10.1016/j.tins.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/28/2024] [Accepted: 06/26/2024] [Indexed: 07/27/2024]
Abstract
Intellectual disability is defined as limitations in cognitive and adaptive behavior that often arise during development. Disordered sleep is common in intellectual disability and, given the importance of sleep for cognitive function, it may contribute to other behavioral phenotypes. Animal models of intellectual disability, in particular of monogenic intellectual disability syndromes (MIDS), recapitulate many disease phenotypes and have been invaluable for linking some of these phenotypes to specific molecular pathways. An emerging feature of MIDS, in both animal models and humans, is the prevalence of metabolic abnormalities, which could be relevant for behavior. Focusing on specific MIDS that have been molecularly characterized, we review sleep, circadian, and metabolic phenotypes in animal models and humans and propose that altered metabolic state contributes to the abnormal sleep/circadian phenotypes in MIDS.
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Affiliation(s)
- Mariela Lopez Valencia
- Chronobiology and Sleep Institute, Perelman Medical School of University of Pennsylvania, Philadelphia, PA, USA
| | - Folasade A Sofela
- Chronobiology and Sleep Institute, Perelman Medical School of University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas A Jongens
- Chronobiology and Sleep Institute, Perelman Medical School of University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Autism Spectrum Program of Excellence, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Amita Sehgal
- Chronobiology and Sleep Institute, Perelman Medical School of University of Pennsylvania, Philadelphia, PA, USA; Howard Hughes Medical Institute, Philadelphia, PA, USA.
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4
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Park SJ, Murphy KR, Ja WW. Energy Deficit is a Key Driver of Sleep Homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596666. [PMID: 38979352 PMCID: PMC11230206 DOI: 10.1101/2024.05.30.596666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Sleep and feeding are vital homeostatic behaviors, and disruptions in either can result in substantial metabolic consequences. Distinct neuronal manipulations in Drosophila can dissociate sleep loss from subsequent homeostatic rebound, offering an optimal platform to examine the precise interplay between these fundamental behaviors. Here, we investigate concomitant changes in sleep and food intake in individual animals, as well as respiratory metabolic expenditure, that accompany behavioral and genetic manipulations that induce sleep loss in Drosophila melanogaster. We find that sleep disruptions resulting in energy deficit through increased metabolic expenditure and manifested as increased food intake were consistently followed by rebound sleep. In contrast, "soft" sleep loss, which does not induce rebound sleep, is not accompanied by increased metabolism and food intake. Our results demonstrate that homeostatic sleep rebound is linked to energy deficit accrued during sleep loss. Collectively, these findings support the notion that sleep functions to conserve energy and highlight the need to examine the effects of metabolic therapeutics on sleep.
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Affiliation(s)
- Scarlet J Park
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences, Jupiter, FL 33458, USA
- Current affiliation: Nova Southeastern University, Palm Beach Gardens, FL 33410, USA
| | - Keith R Murphy
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, USA
- Integrative Biology and Neuroscience Program, Florida Atlantic University, Jupiter FL 33458, USA
- Current affiliation: Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - William W Ja
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences, Jupiter, FL 33458, USA
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5
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Stahl A, Tomchik SM. Modeling neurodegenerative and neurodevelopmental disorders in the Drosophila mushroom body. Learn Mem 2024; 31:a053816. [PMID: 38876485 PMCID: PMC11199955 DOI: 10.1101/lm.053816.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 05/01/2024] [Indexed: 06/16/2024]
Abstract
The common fruit fly Drosophila melanogaster provides a powerful platform to investigate the genetic, molecular, cellular, and neural circuit mechanisms of behavior. Research in this model system has shed light on multiple aspects of brain physiology and behavior, from fundamental neuronal function to complex behaviors. A major anatomical region that modulates complex behaviors is the mushroom body (MB). The MB integrates multimodal sensory information and is involved in behaviors ranging from sensory processing/responses to learning and memory. Many genes that underlie brain disorders are conserved, from flies to humans, and studies in Drosophila have contributed significantly to our understanding of the mechanisms of brain disorders. Genetic mutations that mimic human diseases-such as Fragile X syndrome, neurofibromatosis type 1, Parkinson's disease, and Alzheimer's disease-affect MB structure and function, altering behavior. Studies dissecting the effects of disease-causing mutations in the MB have identified key pathological mechanisms, and the development of a complete connectome promises to add a comprehensive anatomical framework for disease modeling. Here, we review Drosophila models of human neurodevelopmental and neurodegenerative disorders via the effects of their underlying mutations on MB structure, function, and the resulting behavioral alterations.
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Affiliation(s)
- Aaron Stahl
- Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA
| | - Seth M Tomchik
- Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa 52242, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242, USA
- Hawk-IDDRC, University of Iowa, Iowa City, Iowa 52242, USA
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6
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Atsoniou K, Giannopoulou E, Georganta EM, Skoulakis EMC. Drosophila Contributions towards Understanding Neurofibromatosis 1. Cells 2024; 13:721. [PMID: 38667335 PMCID: PMC11048932 DOI: 10.3390/cells13080721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 04/28/2024] Open
Abstract
Neurofibromatosis 1 (NF1) is a multisymptomatic disorder with highly variable presentations, which include short stature, susceptibility to formation of the characteristic benign tumors known as neurofibromas, intense freckling and skin discoloration, and cognitive deficits, which characterize most children with the condition. Attention deficits and Autism Spectrum manifestations augment the compromised learning presented by most patients, leading to behavioral problems and school failure, while fragmented sleep contributes to chronic fatigue and poor quality of life. Neurofibromin (Nf1) is present ubiquitously during human development and postnatally in most neuronal, oligodendrocyte, and Schwann cells. Evidence largely from animal models including Drosophila suggests that the symptomatic variability may reflect distinct cell-type-specific functions of the protein, which emerge upon its loss, or mutations affecting the different functional domains of the protein. This review summarizes the contributions of Drosophila in modeling multiple NF1 manifestations, addressing hypotheses regarding the cell-type-specific functions of the protein and exploring the molecular pathways affected upon loss of the highly conserved fly homolog dNf1. Collectively, work in this model not only has efficiently and expediently modelled multiple aspects of the condition and increased understanding of its behavioral manifestations, but also has led to pharmaceutical strategies towards their amelioration.
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Affiliation(s)
- Kalliopi Atsoniou
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
- Laboratory of Experimental Physiology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Eleni Giannopoulou
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
| | - Eirini-Maria Georganta
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
| | - Efthimios M. C. Skoulakis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
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7
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Brown EB, Zhang J, Lloyd E, Lanzon E, Botero V, Tomchik S, Keene AC. Neurofibromin 1 mediates sleep depth in Drosophila. PLoS Genet 2023; 19:e1011049. [PMID: 38091360 PMCID: PMC10763969 DOI: 10.1371/journal.pgen.1011049] [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: 09/11/2023] [Revised: 01/03/2024] [Accepted: 11/03/2023] [Indexed: 01/04/2024] Open
Abstract
Neural regulation of sleep and metabolic homeostasis are critical in many aspects of human health. Despite extensive epidemiological evidence linking sleep dysregulation with obesity, diabetes, and metabolic syndrome, little is known about the neural and molecular basis for the integration of sleep and metabolic function. The RAS GTPase-activating gene Neurofibromin (Nf1) has been implicated in the regulation of sleep and metabolic rate, raising the possibility that it serves to integrate these processes, but the effects on sleep consolidation and physiology remain poorly understood. A key hallmark of sleep depth in mammals and flies is a reduction in metabolic rate during sleep. Here, we examine multiple measures of sleep quality to determine the effects of Nf1 on sleep-dependent changes in arousal threshold and metabolic rate. Flies lacking Nf1 fail to suppress metabolic rate during sleep, raising the possibility that loss of Nf1 prevents flies from integrating sleep and metabolic state. Sleep of Nf1 mutant flies is fragmented with a reduced arousal threshold in Nf1 mutants, suggesting Nf1 flies fail to enter deep sleep. The effects of Nf1 on sleep can be localized to a subset of neurons expressing the GABAA receptor Rdl. Sleep loss has been associated with changes in gut homeostasis in flies and mammals. Selective knockdown of Nf1 in Rdl-expressing neurons within the nervous system increases gut permeability and reactive oxygen species (ROS) in the gut, raising the possibility that loss of sleep quality contributes to gut dysregulation. Together, these findings suggest Nf1 acts in GABA-sensitive neurons to modulate sleep depth in Drosophila.
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Affiliation(s)
- Elizabeth B. Brown
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- Department of Biological Sciences, Florida State University, Tallahassee, Florida, United States of America
| | - Jiwei Zhang
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Evan Lloyd
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Elizabeth Lanzon
- Jupiter Life Science Initiative, Florida Atlantic University, Jupiter, Florida, United States of America
| | - Valentina Botero
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Seth Tomchik
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Alex C. Keene
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
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8
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Dyson A, Ryan M, Garg S, Evans DG, Baines RA. Loss of NF1 in Drosophila Larvae Causes Tactile Hypersensitivity and Impaired Synaptic Transmission at the Neuromuscular Junction. J Neurosci 2022; 42:9450-9472. [PMID: 36344265 PMCID: PMC9794380 DOI: 10.1523/jneurosci.0562-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 09/20/2022] [Accepted: 09/23/2022] [Indexed: 11/09/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition in which the mechanisms underlying its core symptomatology are largely unknown. Studying animal models of monogenic syndromes associated with ASD, such as neurofibromatosis type 1 (NF1), can offer insights into its etiology. Here, we show that loss of function of the Drosophila NF1 ortholog results in tactile hypersensitivity following brief mechanical stimulation in the larva (mixed sexes), paralleling the sensory abnormalities observed in individuals with ASD. Mutant larvae also exhibit synaptic transmission deficits at the glutamatergic neuromuscular junction (NMJ), with increased spontaneous but reduced evoked release. While the latter is homeostatically compensated for by a postsynaptic increase in input resistance, the former is consistent with neuronal hyperexcitability. Indeed, diminished expression of NF1 specifically within central cholinergic neurons induces both excessive neuronal firing and tactile hypersensitivity, suggesting the two may be linked. Furthermore, both impaired synaptic transmission and behavioral deficits are fully rescued via knock-down of Ras proteins. These findings validate NF1 -/- Drosophila as a tractable model of ASD with the potential to elucidate important pathophysiological mechanisms.SIGNIFICANCE STATEMENT Autism spectrum disorder (ASD) affects 1-2% of the overall population and can considerably impact an individual's quality of life. However, there are currently no treatments available for its core symptoms, largely because of a poor understanding of the underlying mechanisms involved. Examining how loss of function of the ASD-associated NF1 gene affects behavior and physiology in Drosophila may shed light on this. In this study, we identify a novel, ASD-relevant behavioral phenotype in NF1 -/- larvae, namely an enhanced response to mechanical stimulation, which is associated with Ras-dependent synaptic transmission deficits indicative of neuronal hyperexcitability. Such insights support the use of Drosophila neurofibromatosis type 1 (NF1) models in ASD research and may provide outputs for genetic or pharmacological screens in future studies.
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Affiliation(s)
- Alex Dyson
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
| | - Megan Ryan
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
| | - Shruti Garg
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
- Child & Adolescent Mental Health Services, Royal Manchester Children's Hospital, Central Manchester University Hospitals National Health Service Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, M13 9WL, United Kingdom
| | - D Gareth Evans
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
| | - Richard A Baines
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
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Mahadevan J, Sud R, Nadella RK, Vani P, Subramaniam AG, Paul P, Ganapathy A, Mannan AU, Chandru V, Viswanath B, Purushottam M, Jain S. Targeted Sequencing Detects Variants That May Contribute to the Risk of Neuropsychiatric Disorders. Indian J Psychol Med 2022; 44:516-522. [PMID: 36157006 PMCID: PMC9460021 DOI: 10.1177/0253717621993672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Jayant Mahadevan
- Dept. of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Reeteka Sud
- Molecular Genetics Laboratory, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Ravi Kumar Nadella
- Dept. of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Pulaparambil Vani
- Dept. of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Anand G Subramaniam
- Molecular Genetics Laboratory, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Pradip Paul
- Molecular Genetics Laboratory, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Aparna Ganapathy
- Strand Center for Genomics and Personalized Medicine, Strand Life Sciences, Bengaluru, Karnataka, India
| | - Ashraf U Mannan
- Strand Center for Genomics and Personalized Medicine, Strand Life Sciences, Bengaluru, Karnataka, India
| | - Vijay Chandru
- Strand Center for Genomics and Personalized Medicine, Strand Life Sciences, Bengaluru, Karnataka, India.,Centre for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Biju Viswanath
- Dept. of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India.,Molecular Genetics Laboratory, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Meera Purushottam
- Molecular Genetics Laboratory, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Sanjeev Jain
- Dept. of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India.,Molecular Genetics Laboratory, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
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10
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Miller AH, Halloran MC. Mechanistic insights from animal models of neurofibromatosis type 1 cognitive impairment. Dis Model Mech 2022; 15:276464. [PMID: 36037004 PMCID: PMC9459395 DOI: 10.1242/dmm.049422] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal-dominant neurogenetic disorder caused by mutations in the gene neurofibromin 1 (NF1). NF1 predisposes individuals to a variety of symptoms, including peripheral nerve tumors, brain tumors and cognitive dysfunction. Cognitive deficits can negatively impact patient quality of life, especially the social and academic development of children. The neurofibromin protein influences neural circuits via diverse cellular signaling pathways, including through RAS, cAMP and dopamine signaling. Although animal models have been useful in identifying cellular and molecular mechanisms that regulate NF1-dependent behaviors, translating these discoveries into effective treatments has proven difficult. Clinical trials measuring cognitive outcomes in patients with NF1 have mainly targeted RAS signaling but, unfortunately, resulted in limited success. In this Review, we provide an overview of the structure and function of neurofibromin, and evaluate several cellular and molecular mechanisms underlying neurofibromin-dependent cognitive function, which have recently been delineated in animal models. A better understanding of neurofibromin roles in the development and function of the nervous system will be crucial for identifying new therapeutic targets for the various cognitive domains affected by NF1. Summary: Neurofibromin influences neural circuits through RAS, cAMP and dopamine signaling. Exploring the mechanisms underlying neurofibromin-dependent behaviors in animal models might enable future treatment of the various cognitive deficits that are associated with neurofibromatosis type 1.
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Affiliation(s)
- Andrew H Miller
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA.,Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA.,Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Mary C Halloran
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA.,Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
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11
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Cook K, Parks A. The international exchange of Drosophila melanogaster strains. REV SCI TECH OIE 2022; 41:82-90. [PMID: 35925634 PMCID: PMC10116490 DOI: 10.20506/rst.41.1.3305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Drosophila melanogaster has been a model organism for experimental research for more than a century, and the knowledge and associated genetic technologies accumulated around this species make it extremely important to contemporary biomedical research. A large international community of highly collaborative scientists investigate a remarkable diversity of biological problems using genetically characterised strains of Drosophila, and frequently exchange these strains across borders. Despite its importance to the study of fundamental biological processes and human disease-related cellular mechanisms, and the fact that it presents minimal health, agricultural or environmental risks, Drosophila can be difficult to import. The authors argue that streamlined regulations and practices would benefit biomedical research by lowering costs and increasing efficiencies.
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Affiliation(s)
- K.R. Cook
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, Indiana, 47405-7005, United States of America
| | - A.L. Parks
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, Indiana, 47405-7005, United States of America
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12
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Nakagawa H, Maehara S, Kume K, Ohta H, Tomita J. Biological functions of α2-adrenergic-like octopamine receptor in Drosophila melanogaster. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12807. [PMID: 35411674 PMCID: PMC9744561 DOI: 10.1111/gbb.12807] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 11/28/2022]
Abstract
Octopamine regulates various physiological phenomena including memory, sleep, grooming and aggression in insects. In Drosophila, four types of octopamine receptors have been identified: Oamb, Oct/TyrR, OctβR and Octα2R. Among these receptors, Octα2R was recently discovered and pharmacologically characterized. However, the effects of the receptor on biological functions are still unknown. Here, we showed that Octα2R regulated several behaviors related to octopamine signaling. Octα2R hypomorphic mutant flies showed a significant decrease in locomotor activity. We found that Octα2R expressed in the pars intercerebralis, which is a brain region projected by octopaminergic neurons, is involved in control of the locomotor activity. Besides, Octα2R hypomorphic mutants increased time and frequency of grooming and inhibited starvation-induced hyperactivity. These results indicated that Octα2R expressed in the central nervous system is responsible for the involvement in physiological functions.
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Affiliation(s)
- Hiroyuki Nakagawa
- Department of Neuropharmacology, Graduate School of Pharmaceutical SciencesNagoya City UniversityNagoyaJapan
| | - Shiori Maehara
- Faculty of Advanced Science and TechnologyKumamoto UniversityKumamotoJapan
| | - Kazuhiko Kume
- Department of Neuropharmacology, Graduate School of Pharmaceutical SciencesNagoya City UniversityNagoyaJapan
| | - Hiroto Ohta
- Faculty of Advanced Science and TechnologyKumamoto UniversityKumamotoJapan,Department of Applied Microbial Engineering, Faculty of Life SciencesSojo UniversityKumamotoJapan
| | - Jun Tomita
- Department of Neuropharmacology, Graduate School of Pharmaceutical SciencesNagoya City UniversityNagoyaJapan
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13
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Somatilaka BN, Sadek A, McKay RM, Le LQ. Malignant peripheral nerve sheath tumor: models, biology, and translation. Oncogene 2022; 41:2405-2421. [PMID: 35393544 PMCID: PMC9035132 DOI: 10.1038/s41388-022-02290-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/16/2022] [Accepted: 03/21/2022] [Indexed: 01/29/2023]
Abstract
Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, invasive cancer that comprise around 10% of all soft tissue sarcomas and develop in about 8-13% of patients with Neurofibromatosis Type 1. They are associated with poor prognosis and are the leading cause of mortality in NF1 patients. MPNSTs can also develop sporadically or following exposure to radiation. There is currently no effective targeted therapy to treat MPNSTs and surgical removal remains the mainstay treatment. Unfortunately, surgery is not always possible due to the size and location of the tumor, thus, a better understanding of MPNST initiation and development is required to design novel therapeutics. Here, we provide an overview of MPNST biology and genetics, discuss findings regarding the developmental origin of MPNST, and summarize the various model systems employed to study MPNST. Finally, we discuss current management strategies for MPNST, as well as recent developments in translating basic research findings into potential therapies.
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Affiliation(s)
- Bandarigoda N. Somatilaka
- Department of Dermatology, University of Texas Southwestern
Medical Center at Dallas, Dallas, Texas, 75390-9069, USA
| | - Ali Sadek
- Department of Dermatology, University of Texas Southwestern
Medical Center at Dallas, Dallas, Texas, 75390-9069, USA
| | - Renee M. McKay
- Department of Dermatology, University of Texas Southwestern
Medical Center at Dallas, Dallas, Texas, 75390-9069, USA
| | - Lu Q. Le
- Department of Dermatology, University of Texas Southwestern
Medical Center at Dallas, Dallas, Texas, 75390-9069, USA,Simmons Comprehensive Cancer Center, University of Texas
Southwestern Medical Center at Dallas, Dallas, Texas, 75390-9069, USA,UTSW Comprehensive Neurofibromatosis Clinic, University of
Texas Southwestern Medical Center at Dallas, Dallas, Texas, 75390-9069, USA,Hamon Center for Regenerative Science and Medicine,
University of Texas Southwestern Medical Center at Dallas, Dallas, Texas,
75390-9069, USA,O’Donnell Brain Institute, University of Texas
Southwestern Medical Center at Dallas, Dallas, Texas, 75390-9069, USA
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14
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Anastasaki C, Orozco P, Gutmann DH. RAS and beyond: the many faces of the neurofibromatosis type 1 protein. Dis Model Mech 2022; 15:274437. [PMID: 35188187 PMCID: PMC8891636 DOI: 10.1242/dmm.049362] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Neurofibromatosis type 1 is a rare neurogenetic syndrome, characterized by pigmentary abnormalities, learning and social deficits, and a predisposition for benign and malignant tumor formation caused by germline mutations in the NF1 gene. With the cloning of the NF1 gene and the recognition that the encoded protein, neurofibromin, largely functions as a negative regulator of RAS activity, attention has mainly focused on RAS and canonical RAS effector pathway signaling relevant to disease pathogenesis and treatment. However, as neurofibromin is a large cytoplasmic protein the RAS regulatory domain of which occupies only 10% of its entire coding sequence, both canonical and non-canonical RAS pathway modulation, as well as the existence of potential non-RAS functions, are becoming apparent. In this Special article, we discuss our current understanding of neurofibromin function.
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Affiliation(s)
- Corina Anastasaki
- Department of Neurology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Paola Orozco
- Department of Neurology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St Louis, MO 63110, USA
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15
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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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16
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Botero V, Stanhope BA, Brown EB, Grenci EC, Boto T, Park SJ, King LB, Murphy KR, Colodner KJ, Walker JA, Keene AC, Ja WW, Tomchik SM. Neurofibromin regulates metabolic rate via neuronal mechanisms in Drosophila. Nat Commun 2021; 12:4285. [PMID: 34257279 PMCID: PMC8277851 DOI: 10.1038/s41467-021-24505-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 06/16/2021] [Indexed: 01/21/2023] Open
Abstract
Neurofibromatosis type 1 is a chronic multisystemic genetic disorder that results from loss of function in the neurofibromin protein. Neurofibromin may regulate metabolism, though the underlying mechanisms remain largely unknown. Here we show that neurofibromin regulates metabolic homeostasis in Drosophila via a discrete neuronal circuit. Loss of neurofibromin increases metabolic rate via a Ras GAP-related domain-dependent mechanism, increases feeding homeostatically, and alters lipid stores and turnover kinetics. The increase in metabolic rate is independent of locomotor activity, and maps to a sparse subset of neurons. Stimulating these neurons increases metabolic rate, linking their dynamic activity state to metabolism over short time scales. Our results indicate that neurofibromin regulates metabolic rate via neuronal mechanisms, suggest that cellular and systemic metabolic alterations may represent a pathophysiological mechanism in neurofibromatosis type 1, and provide a platform for investigating the cellular role of neurofibromin in metabolic homeostasis. Neurofibromatosis type 1 (NF1) is a genetic disorder caused by mutations in neurofibromin and associated with disruptions in physiology and behavior. Here the authors show that neurofibromin regulates metabolic homeostasis via a discrete brain circuit in a Drosophila model of NF1.
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Affiliation(s)
- Valentina Botero
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Bethany A Stanhope
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, USA
| | - Elizabeth B Brown
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, USA
| | - Eliza C Grenci
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Tamara Boto
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA.,Department of Physiology, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Scarlet J Park
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Lanikea B King
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Keith R Murphy
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Kenneth J Colodner
- Program in Neuroscience and Behavior, Mount Holyoke College, South Hadley, MA, USA
| | - James A Walker
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Cancer Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, USA
| | - William W Ja
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, USA.
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17
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Georganta EM, Moressis A, Skoulakis EMC. Associative Learning Requires Neurofibromin to Modulate GABAergic Inputs to Drosophila Mushroom Bodies. J Neurosci 2021; 41:5274-5286. [PMID: 33972401 PMCID: PMC8211548 DOI: 10.1523/jneurosci.1605-20.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 04/12/2021] [Accepted: 04/15/2021] [Indexed: 12/28/2022] Open
Abstract
Cognitive dysfunction is among the hallmark symptoms of Neurofibromatosis 1, and accordingly, loss of the Drosophila melanogaster ortholog of Neurofibromin 1 (dNf1) precipitates associative learning deficits. However, the affected circuitry in the adult CNS remained unclear and the compromised mechanisms debatable. Although the main evolutionarily conserved function attributed to Nf1 is to inactivate Ras, decreased cAMP signaling on its loss has been thought to underlie impaired learning. Using mixed sex populations, we determine that dNf1 loss results in excess GABAergic signaling to the central for associative learning mushroom body (MB) neurons, apparently suppressing learning. dNf1 is necessary and sufficient for learning within these non-MB neurons, as a dAlk and Ras1-dependent, but PKA-independent modulator of GABAergic neurotransmission. Surprisingly, we also uncovered and discuss a postsynaptic Ras1-dependent, but dNf1-independnet signaling within the MBs that apparently responds to presynaptic GABA levels and contributes to the learning deficit of the mutants.
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Affiliation(s)
- Eirini-Maria Georganta
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming" Vari, 16672, Greece
| | - Anastasios Moressis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming" Vari, 16672, Greece
| | - Efthimios M C Skoulakis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming" Vari, 16672, Greece
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18
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Moscato EH, Dubowy C, Walker JA, Kayser MS. Social Behavioral Deficits with Loss of Neurofibromin Emerge from Peripheral Chemosensory Neuron Dysfunction. Cell Rep 2021; 32:107856. [PMID: 32640222 DOI: 10.1016/j.celrep.2020.107856] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 05/14/2020] [Accepted: 06/04/2020] [Indexed: 12/28/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is a neurodevelopmental disorder associated with social and communicative disabilities. The cellular and circuit mechanisms by which loss of neurofibromin 1 (Nf1) results in social deficits are unknown. Here, we identify social behavioral dysregulation with Nf1 loss in Drosophila. These deficits map to primary dysfunction of a group of peripheral sensory neurons. Nf1 regulation of Ras signaling in adult ppk23+ chemosensory cells is required for normal social behaviors in flies. Loss of Nf1 attenuates ppk23+ neuronal activity in response to pheromones, and circuit-specific manipulation of Nf1 expression or neuronal activity in ppk23+ neurons rescues social deficits. This disrupted sensory processing gives rise to persistent changes in behavior beyond the social interaction, indicating a sustained effect of an acute sensory misperception. Together our data identify a specific circuit mechanism through which Nf1 regulates social behaviors and suggest social deficits in NF1 arise from propagation of sensory misinformation.
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Affiliation(s)
- Emilia H Moscato
- Department of Psychiatry, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine Dubowy
- Department of Psychiatry, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James A Walker
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Matthew S Kayser
- Department of Psychiatry, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA; Chronobiology and Sleep Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA.
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19
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Andrew DR, Moe ME, Chen D, Tello JA, Doser RL, Conner WE, Ghuman JK, Restifo LL. Spontaneous motor-behavior abnormalities in two Drosophila models of neurodevelopmental disorders. J Neurogenet 2020; 35:1-22. [PMID: 33164597 DOI: 10.1080/01677063.2020.1833005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Mutations in hundreds of genes cause neurodevelopmental disorders with abnormal motor behavior alongside cognitive deficits. Boys with fragile X syndrome (FXS), a leading monogenic cause of intellectual disability, often display repetitive behaviors, a core feature of autism. By direct observation and manual analysis, we characterized spontaneous-motor-behavior phenotypes of Drosophila dfmr1 mutants, an established model for FXS. We recorded individual 1-day-old adult flies, with mature nervous systems and prior to the onset of aging, in small arenas. We scored behavior using open-source video-annotation software to generate continuous activity timelines, which were represented graphically and quantitatively. Young dfmr1 mutants spent excessive time grooming, with increased bout number and duration; both were rescued by transgenic wild-type dfmr1+. By two grooming-pattern measures, dfmr1-mutant flies showed elevated repetitions consistent with perseveration, which is common in FXS. In addition, the mutant flies display a preference for grooming posterior body structures, and an increased rate of grooming transitions from one site to another. We raise the possibility that courtship and circadian rhythm defects, previously reported for dfmr1 mutants, are complicated by excessive grooming. We also observed significantly increased grooming in CASK mutants, despite their dramatically decreased walking phenotype. The mutant flies, a model for human CASK-related neurodevelopmental disorders, displayed consistently elevated grooming indices throughout the assay, but transient locomotory activation immediately after placement in the arena. Based on published data identifying FMRP-target transcripts and functional analyses of mutations causing human genetic neurodevelopmental disorders, we propose the following proteins as candidate mediators of excessive repetitive behaviors in FXS: CaMKIIα, NMDA receptor subunits 2A and 2B, NLGN3, and SHANK3. Together, these fly-mutant phenotypes and mechanistic insights provide starting points for drug discovery to identify compounds that reduce dysfunctional repetitive behaviors.
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Affiliation(s)
- David R Andrew
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Department of Biological Sciences, Lycoming College, Williamsport, PA, USA
| | - Mariah E Moe
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Dailu Chen
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Judith A Tello
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA
| | - Rachel L Doser
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - William E Conner
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Jaswinder K Ghuman
- Department of Psychiatry, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Linda L Restifo
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA.,BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, USA
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20
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Yanagawa A, Huang W, Yamamoto A, Wada-Katsumata A, Schal C, Mackay TFC. Genetic Basis of Natural Variation in Spontaneous Grooming in Drosophila melanogaster. G3 (BETHESDA, MD.) 2020; 10:3453-3460. [PMID: 32727922 PMCID: PMC7467001 DOI: 10.1534/g3.120.401360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/28/2020] [Indexed: 12/29/2022]
Abstract
Spontaneous grooming behavior is a component of insect fitness. We quantified spontaneous grooming behavior in 201 sequenced lines of the Drosophila melanogaster Genetic Reference Panel and observed significant genetic variation in spontaneous grooming, with broad-sense heritabilities of 0.25 and 0.24 in females and males, respectively. Although grooming behavior is highly correlated between males and females, we observed significant sex by genotype interactions, indicating that the genetic basis of spontaneous grooming is partially distinct in the two sexes. We performed genome-wide association analyses of grooming behavior, and mapped 107 molecular polymorphisms associated with spontaneous grooming behavior, of which 73 were in or near 70 genes and 34 were over 1 kilobase from the nearest gene. The candidate genes were associated with a wide variety of gene ontology terms, and several of the candidate genes were significantly enriched in a genetic interaction network. We performed functional assessments of 29 candidate genes using RNA interference, and found that 11 affected spontaneous grooming behavior. The genes associated with natural variation in Drosophila grooming are involved with glutamate metabolism (Gdh) and transport (Eaat); interact genetically with (CCKLR-17D1) or are in the same gene family as (PGRP-LA) genes previously implicated in grooming behavior; are involved in the development of the nervous system and other tissues; or regulate the Notch and Epidermal growth factor receptor signaling pathways. Several DGRP lines exhibited extreme grooming behavior. Excessive grooming behavior can serve as a model for repetitive behaviors diagnostic of several human neuropsychiatric diseases.
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Affiliation(s)
- Aya Yanagawa
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
| | - Wen Huang
- Department of Animal Science, Michigan State University, East Lansing, Michigan 48824
| | - Akihiko Yamamoto
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613
| | - Ayako Wada-Katsumata
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613
| | - Coby Schal
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613
| | - Trudy F C Mackay
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, Greenwood, SC 29646
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21
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King LB, Boto T, Botero V, Aviles AM, Jomsky BM, Joseph C, Walker JA, Tomchik SM. Developmental loss of neurofibromin across distributed neuronal circuits drives excessive grooming in Drosophila. PLoS Genet 2020; 16:e1008920. [PMID: 32697780 PMCID: PMC7398555 DOI: 10.1371/journal.pgen.1008920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 08/03/2020] [Accepted: 06/08/2020] [Indexed: 02/06/2023] Open
Abstract
Neurofibromatosis type 1 is a monogenetic disorder that predisposes individuals to tumor formation and cognitive and behavioral symptoms. The neuronal circuitry and developmental events underlying these neurological symptoms are unknown. To better understand how mutations of the underlying gene (NF1) drive behavioral alterations, we have examined grooming in the Drosophila neurofibromatosis 1 model. Mutations of the fly NF1 ortholog drive excessive grooming, and increased grooming was observed in adults when Nf1 was knocked down during development. Furthermore, intact Nf1 Ras GAP-related domain signaling was required to maintain normal grooming. The requirement for Nf1 was distributed across neuronal circuits, which were additive when targeted in parallel, rather than mapping to discrete microcircuits. Overall, these data suggest that broadly-distributed alterations in neuronal function during development, requiring intact Ras signaling, drive key Nf1-mediated behavioral alterations. Thus, global developmental alterations in brain circuits/systems function may contribute to behavioral phenotypes in neurofibromatosis type 1.
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Affiliation(s)
- Lanikea B. King
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Tamara Boto
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Valentina Botero
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Ari M. Aviles
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
- Honors College, Florida Atlantic University, Jupiter, Florida, United States of America
| | - Breanna M. Jomsky
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
- Honors College, Florida Atlantic University, Jupiter, Florida, United States of America
| | - Chevara Joseph
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
- Honors College, Florida Atlantic University, Jupiter, Florida, United States of America
| | - James A. Walker
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Cambridge, Massachusetts, United States of America
| | - Seth M. Tomchik
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
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22
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Tumkaya T, Ott S, Claridge-Chang A. A systematic review of Drosophila short-term-memory genetics: Meta-analysis reveals robust reproducibility. Neurosci Biobehav Rev 2018; 95:361-382. [PMID: 30077573 DOI: 10.1016/j.neubiorev.2018.07.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 07/07/2018] [Accepted: 07/25/2018] [Indexed: 12/19/2022]
Abstract
Geneticists use olfactory conditioning in Drosophila to identify learning genes; however, little is known about how these genes are integrated into short-term memory (STM) pathways. Here, we investigated the hypothesis that the STM evidence base is weak. We performed systematic review and meta-analysis of the field. Using metrics to quantify variation between discovery articles and follow-up studies, we found that seven genes were both highly replicated, and highly reproducible. However, ∼80% of STM genes have never been replicated. While only a few studies investigated interactions, the reviewed genes could account for >1000% memory. This large summed effect size could indicate irreproducibility, many shared pathways, or that current assay protocols lack the specificity needed to identify core plasticity genes. Mechanistic theories of memory will require the convergence of evidence from system, circuit, cellular, molecular, and genetic experiments; systematic data synthesis is an essential tool for integrated neuroscience.
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Affiliation(s)
- Tayfun Tumkaya
- Institute for Molecular and Cell Biology, A(⁎)STAR, Singapore; Department of Physiology, National University of Singapore, Singapore
| | - Stanislav Ott
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore
| | - Adam Claridge-Chang
- Institute for Molecular and Cell Biology, A(⁎)STAR, Singapore; Department of Physiology, National University of Singapore, Singapore; Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore.
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23
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Sharafi P, Ayter S. Possible modifier genes in the variation of neurofibromatosis type 1 clinical phenotypes. J Neurogenet 2018; 32:65-77. [PMID: 29644913 DOI: 10.1080/01677063.2018.1456538] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Neurofibromatosis type 1 (NF1) is the most common neurogenetic disorder worldwide, caused by mutations in the (NF1) gene. Although NF1 is a single-gene disorder with autosomal-dominant inheritance, its clinical expression is highly variable and unpredictable. NF1 patients have the highest known mutation rate among all human disorders, with no clear genotype-phenotype correlations. Therefore, variations in NF1 mutations may not correlate with the variations in clinical phenotype. Indeed, for the same mutation, some NF1 patients may develop severe clinical symptoms whereas others will develop a mild phenotype. Variations in the mutant NF1 allele itself cannot account for all of the disease variability, indicating a contribution of modifier genes, environmental factors, or their combination. Considering the gene structure and the interaction of neurofibromin protein with cellular components, there are many possible candidate modifier genes. This review aims to provide an overview of the potential modifier genes contributing to NF1 clinical variability.
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Affiliation(s)
- Parisa Sharafi
- a Faculty of Medicine , TOBB University of Economics and Technology , Ankara , Turkey
| | - Sükriye Ayter
- a Faculty of Medicine , TOBB University of Economics and Technology , Ankara , Turkey
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24
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Qiao B, Li C, Allen VW, Shirasu-Hiza M, Syed S. Automated analysis of long-term grooming behavior in Drosophila using a k-nearest neighbors classifier. eLife 2018; 7:e34497. [PMID: 29485401 PMCID: PMC5860874 DOI: 10.7554/elife.34497] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/26/2018] [Indexed: 12/14/2022] Open
Abstract
Despite being pervasive, the control of programmed grooming is poorly understood. We addressed this gap by developing a high-throughput platform that allows long-term detection of grooming in Drosophila melanogaster. In our method, a k-nearest neighbors algorithm automatically classifies fly behavior and finds grooming events with over 90% accuracy in diverse genotypes. Our data show that flies spend ~13% of their waking time grooming, driven largely by two major internal programs. One of these programs regulates the timing of grooming and involves the core circadian clock components cycle, clock, and period. The second program regulates the duration of grooming and, while dependent on cycle and clock, appears to be independent of period. This emerging dual control model in which one program controls timing and another controls duration, resembles the two-process regulatory model of sleep. Together, our quantitative approach presents the opportunity for further dissection of mechanisms controlling long-term grooming in Drosophila.
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Affiliation(s)
- Bing Qiao
- Department of PhysicsUniversity of MiamiCoral GablesUnited States
| | - Chiyuan Li
- Department of PhysicsUniversity of MiamiCoral GablesUnited States
| | - Victoria W Allen
- Department of Genetics and DevelopmentColumbia UniversityNew YorkUnited States
| | - Mimi Shirasu-Hiza
- Department of Genetics and DevelopmentColumbia UniversityNew YorkUnited States
| | - Sheyum Syed
- Department of PhysicsUniversity of MiamiCoral GablesUnited States
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25
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Keebaugh ES, Park JH, Su C, Yamada R, Ja WW. Nutrition Influences Caffeine-Mediated Sleep Loss in Drosophila. Sleep 2017; 40:4209550. [PMID: 29029291 PMCID: PMC5804985 DOI: 10.1093/sleep/zsx146] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Study objectives Plant-derived caffeine is regarded as a defensive compound produced to prevent herbivory. Caffeine is generally repellent to insects and often used to study the neurological basis for aversive responses in the model insect, Drosophila melanogaster. Caffeine is also studied for its stimulatory properties where sleep or drowsiness is suppressed across a range of species. Since limiting access to food also inhibits fly sleep-an effect known as starvation-induced sleep suppression-we tested whether aversion to caffeinated food results in reduced nutrient intake and assessed how this might influence fly studies on the stimulatory effects of caffeine. Methods We measured sleep and total consumption during the first 24 hours of exposure to caffeinated diets containing a range of sucrose concentrations to determine the relative influence of caffeine and nutrient ingestion on sleep. Experiments were replicated using three fly strains. Results Caffeine reduced total consumption and nighttime sleep, but only at intermediate sucrose concentrations. Although sleep can be modeled by an exponential dose response to nutrient intake, caffeine-mediated sleep loss cannot be explained by absolute caffeine or sucrose ingestion alone. Instead, reduced sleep strongly correlates with changes in total consumption due to caffeine. Other bitter compounds phenocopy the effect of caffeine on sleep and food intake. Conclusions Our results suggest that a major effect of dietary caffeine is on fly feeding behavior. Changes in feeding behavior may drive caffeine-mediated sleep loss. Future studies using psychoactive compounds should consider the potential impact of nutrition when investigating effects on sleep.
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Affiliation(s)
- Erin S Keebaugh
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL
- Center on Aging, The Scripps Research Institute, Jupiter, FL
| | - Jin Hong Park
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL
- Center on Aging, The Scripps Research Institute, Jupiter, FL
- Scripps Graduate Program, The Scripps Research Institute, Jupiter, FL
| | - Chenchen Su
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL
- Center on Aging, The Scripps Research Institute, Jupiter, FL
| | - Ryuichi Yamada
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL
- Center on Aging, The Scripps Research Institute, Jupiter, FL
| | - William W Ja
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL
- Center on Aging, The Scripps Research Institute, Jupiter, FL
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Asjad HMM, Kasture A, El-Kasaby A, Sackel M, Hummel T, Freissmuth M, Sucic S. Pharmacochaperoning in a Drosophila model system rescues human dopamine transporter variants associated with infantile/juvenile parkinsonism. J Biol Chem 2017; 292:19250-19265. [PMID: 28972153 PMCID: PMC5702666 DOI: 10.1074/jbc.m117.797092] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/06/2017] [Indexed: 12/19/2022] Open
Abstract
Point mutations in the gene encoding the human dopamine transporter (hDAT, SLC6A3) cause a syndrome of infantile/juvenile dystonia and parkinsonism. To unravel the molecular mechanism underlying these disorders and investigate possible pharmacological therapies, here we examined 13 disease-causing DAT mutants that were retained in the endoplasmic reticulum when heterologously expressed in HEK293 cells. In three of these mutants, i.e. hDAT-V158F, hDAT-G327R, and hDAT-L368Q, the folding deficit was remedied with the pharmacochaperone noribogaine or the heat shock protein 70 (HSP70) inhibitor pifithrin-μ such that endoplasmic reticulum export of and radioligand binding and substrate uptake by these DAT mutants were restored. In Drosophila melanogaster, DAT deficiency results in reduced sleep. We therefore exploited the power of targeted transgene expression of mutant hDAT in Drosophila to explore whether these hDAT mutants could also be pharmacologically rescued in an intact organism. Noribogaine or pifithrin-μ treatment supported hDAT delivery to the presynaptic terminals of dopaminergic neurons and restored sleep to normal length in DAT-deficient (fumin) Drosophila lines expressing hDAT-V158F or hDAT-G327R. In contrast, expression of hDAT-L368Q in the Drosophila DAT mutant background caused developmental lethality, indicating a toxic action not remedied by pharmacochaperoning. Our observations identified those mutations most likely amenable to pharmacological rescue in the affected children. In addition, our findings also highlight the challenges of translating insights from pharmacochaperoning in cell culture to the clinical situation. Because of the evolutionary conservation in dopaminergic neurotransmission between Drosophila and people, pharmacochaperoning of DAT in D. melanogaster may allow us to bridge that gap.
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Affiliation(s)
- H M Mazhar Asjad
- From the Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria and
| | - Ameya Kasture
- From the Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria and
| | - Ali El-Kasaby
- From the Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria and
| | - Michael Sackel
- the Department of Neurobiology, University of Vienna, A-1090 Vienna, Austria
| | - Thomas Hummel
- the Department of Neurobiology, University of Vienna, A-1090 Vienna, Austria
| | - Michael Freissmuth
- From the Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria and
| | - Sonja Sucic
- From the Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria and
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Abstract
Drosophila grooming behavior is a complex multi-step locomotor program that requires coordinated movement of both forelegs and hindlegs. Here we present a grooming assay protocol and novel chamber design that is cost-efficient and scalable for either small or large-scale studies of Drosophila grooming. Flies are dusted all over their body with Brilliant Yellow dye and given time to remove the dye from their bodies within the chamber. Flies are then deposited in a set volume of ethanol to solubilize the dye. The relative spectral absorbance of dye-ethanol samples for groomed versus ungroomed animals are measured and recorded. The protocol yields quantitative data of dye accumulation for individual flies, which can be easily averaged and compared across samples. This allows experimental designs to easily evaluate grooming ability for mutant animal studies or circuit manipulations. This efficient procedure is both versatile and scalable. We show work-flow of the protocol and comparative data between WT animals and mutant animals for the Drosophila type I Dopamine Receptor (DopR).
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28
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Murphy KR, Deshpande SA, Yurgel ME, Quinn JP, Weissbach JL, Keene AC, Dawson-Scully K, Huber R, Tomchik SM, Ja WW. Postprandial sleep mechanics in Drosophila. eLife 2016; 5. [PMID: 27873574 PMCID: PMC5119887 DOI: 10.7554/elife.19334] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 10/27/2016] [Indexed: 01/10/2023] Open
Abstract
Food consumption is thought to induce sleepiness. However, little is known about how postprandial sleep is regulated. Here, we simultaneously measured sleep and food intake of individual flies and found a transient rise in sleep following meals. Depending on the amount consumed, the effect ranged from slightly arousing to strongly sleep inducing. Postprandial sleep was positively correlated with ingested volume, protein, and salt—but not sucrose—revealing meal property-specific regulation. Silencing of leucokinin receptor (Lkr) neurons specifically reduced sleep induced by protein consumption. Thermogenetic stimulation of leucokinin (Lk) neurons decreased whereas Lk downregulation by RNAi increased postprandial sleep, suggestive of an inhibitory connection in the Lk-Lkr circuit. We further identified a subset of non-leucokininergic cells proximal to Lkr neurons that rhythmically increased postprandial sleep when silenced, suggesting that these cells are cyclically gated inhibitory inputs to Lkr neurons. Together, these findings reveal the dynamic nature of postprandial sleep. DOI:http://dx.doi.org/10.7554/eLife.19334.001 Many of us have experienced feelings of sleepiness after a large meal. However, there is little scientific evidence that this “food coma” effect is real. If it is, it may vary between individuals, or depend on the type of food consumed. This variability makes it difficult to study the causes of post-meal sleepiness. Murphy et al. have now developed a system that can measure fruit fly sleep and feeding behavior at the same time. Recordings using this system reveal that after a meal, flies sleep more for a short period before returning to a normal state of wakefulness. The sleep period lasts around 20-40 minutes, with flies that ate more generally sleeping more. Further investigation revealed that salty or protein-rich foods promote sleep, whereas sugary foods do not. By using genetic tools to turn on and off neurons in the fly brain, Murphy et al. identified a number of brain circuits that play a role in controlling post-meal sleepiness. Some of these respond specifically to the consumption of protein. Others are sensitive to the fruit fly’s internal clock, reducing post-meal sleepiness only around dusk. Thus, post-meal sleepiness can be regulated in a number of different ways. Future experiments are now needed to explore the genes and circuits that enable meal size and the protein or salt content of food to drive sleep. In nature, sleep is likely a vulnerable state for animals. Thus, another challenge will be to uncover why post-meal sleep is important. Does sleeping after a meal boost digestion? Or might it help animals to form memories about a food source, making it easier to find similar food in the future? DOI:http://dx.doi.org/10.7554/eLife.19334.002
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Affiliation(s)
- Keith R Murphy
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States.,Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States.,Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Sonali A Deshpande
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States
| | - Maria E Yurgel
- Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States
| | - James P Quinn
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States
| | - Jennifer L Weissbach
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States
| | - Alex C Keene
- Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States
| | - Ken Dawson-Scully
- Program in Integrative Biology and Neuroscience, Florida Atlantic University, Jupiter, United States
| | - Robert Huber
- Radcliffe Institute for Advanced Study, Harvard University, Cambridge, United States.,JP Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, United States
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - William W Ja
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, United States.,Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
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