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Peng JJ, Lin SH, Liu YT, Lin HC, Li TN, Yao CK. A circuit-dependent ROS feedback loop mediates glutamate excitotoxicity to sculpt the Drosophila motor system. eLife 2019; 8:47372. [PMID: 31318331 PMCID: PMC6682402 DOI: 10.7554/elife.47372] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/17/2019] [Indexed: 12/12/2022] Open
Abstract
Overproduction of reactive oxygen species (ROS) is known to mediate glutamate excitotoxicity in neurological diseases. However, how ROS burdens can influence neural circuit integrity remains unclear. Here, we investigate the impact of excitotoxicity induced by depletion of Drosophila Eaat1, an astrocytic glutamate transporter, on locomotor central pattern generator (CPG) activity, neuromuscular junction architecture, and motor function. We show that glutamate excitotoxicity triggers a circuit-dependent ROS feedback loop to sculpt the motor system. Excitotoxicity initially elevates ROS, thereby inactivating cholinergic interneurons and consequently changing CPG output activity to overexcite motor neurons and muscles. Remarkably, tonic motor neuron stimulation boosts muscular ROS, gradually dampening muscle contractility to feedback-enhance ROS accumulation in the CPG circuit and subsequently exacerbate circuit dysfunction. Ultimately, excess premotor excitation of motor neurons promotes ROS-activated stress signaling that alters neuromuscular junction architecture. Collectively, our results reveal that excitotoxicity-induced ROS can perturb motor system integrity through a circuit-dependent mechanism.
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Affiliation(s)
- Jhan-Jie Peng
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Shih-Han Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Yu-Tzu Liu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Hsin-Chieh Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Tsai-Ning Li
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Chi-Kuang Yao
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan, Republic of China
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Perić-Mataruga V, Petković B, Ilijin L, Mrdaković M, Dronjak Čučaković S, Todorović D, Vlahović M. Cadmium and high temperature effects on brain and behaviour of Lymantria dispar L. caterpillars originating from polluted and less-polluted forests. CHEMOSPHERE 2017; 185:628-636. [PMID: 28728120 DOI: 10.1016/j.chemosphere.2017.07.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
Insects brain as a part of nervous system is the first-line of fast stress response that integrate stress signals to regulate all aspects of insect physiology and behaviour. The cadmium (Cd) bioaccumulation factor (BF), activity of the neurotoxicity biomarker acetylcholinesterase (AChE), dopamine content, expression and amount of Hsp70 in the brain and locomotor activity were evaluated in the 4th instar of Lymantria dispar L. caterpillars fed a Cd supplemented diet and reared in an optimal temperature regime (23 °C) and/or exposed to high temperature (28 °C). The insects originated from two forests, one close to "Nikola Tesla" thermoelectric power plant, Obrenovac (polluted population), and the other Kosmaj mountain (less-polluted population, far from any industrial region). The Cd BF was higher in the less-polluted than in the polluted population especially at the high ambient temperature. AChE activity and dopamine content were changed in the brains of L. dispar from both populations in the same manner. Hsp70 concentration in caterpillar brains showed opposite trends, a decrease in the less-polluted and an increase in the polluted population. Locomotor activity was modified in both Lymantria dispar populations, but the pattern of changes depended on the stressors and their combined effect. ACh activity and dopamine content are sensitive parameters to Cd exposure, regardless of pollutant experience, and might be promising biomarkers in monitoring forest ecosystems.
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Affiliation(s)
- Vesna Perić-Mataruga
- Department of Insect Physiology and Biochemistry, University of Belgrade, Institute for Biological Research "Siniša Stanković", Despot Stefan Blvd. 142, 11060, Belgrade, Serbia.
| | - Branka Petković
- Department of Neurophysiology, University of Belgrade, Institute for Biological Research "Siniša Stanković", Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
| | - Larisa Ilijin
- Department of Insect Physiology and Biochemistry, University of Belgrade, Institute for Biological Research "Siniša Stanković", Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
| | - Marija Mrdaković
- Department of Insect Physiology and Biochemistry, University of Belgrade, Institute for Biological Research "Siniša Stanković", Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
| | - Slađana Dronjak Čučaković
- Institute of Nuclear Sciences "Vinca", Laboratory of Molecular Biology and Endocrinology, University of Belgrade, Mike Petrovića Alasa 12-14, 11001, Belgrade, Serbia
| | - Dajana Todorović
- Department of Insect Physiology and Biochemistry, University of Belgrade, Institute for Biological Research "Siniša Stanković", Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
| | - Milena Vlahović
- Department of Insect Physiology and Biochemistry, University of Belgrade, Institute for Biological Research "Siniša Stanković", Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
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McGrath LL, Vollmer SV, Kaluziak ST, Ayers J. De novo transcriptome assembly for the lobster Homarus americanus and characterization of differential gene expression across nervous system tissues. BMC Genomics 2016; 17:63. [PMID: 26772543 PMCID: PMC4715275 DOI: 10.1186/s12864-016-2373-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 01/06/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The American lobster, Homarus americanus, is an important species as an economically valuable fishery, a key member in marine ecosystems, and a well-studied model for central pattern generation, the neural networks that control rhythmic motor patterns. Despite multi-faceted scientific interest in this species, currently our genetic resources for the lobster are limited. In this study, we de novo assemble a transcriptome for Homarus americanus using central nervous system (CNS), muscle, and hybrid neurosecretory tissues and compare gene expression across these tissue types. In particular, we focus our analysis on genes relevant to central pattern generation and the identity of the neurons in a neural network, which is defined by combinations of genes distinguishing the neuronal behavior and phenotype, including ion channels, neurotransmitters, neuromodulators, receptors, transcription factors, and other gene products. RESULTS Using samples from the central nervous system (brain, abdominal ganglia), abdominal muscle, and heart (cardiac ganglia, pericardial organs, muscle), we used RNA-Seq to characterize gene expression patterns across tissues types. We also compared control tissues with those challenged with the neuropeptide proctolin in vivo. Our transcriptome generated 34,813 transcripts with known protein annotations. Of these, 5,000-10,000 of annotated transcripts were significantly differentially expressed (DE) across tissue types. We found 421 transcripts for ion channels and identified receptors and/or proteins for over 20 different neurotransmitters and neuromodulators. Results indicated tissue-specific expression of select neuromodulator (allostatin, myomodulin, octopamine, nitric oxide) and neurotransmitter (glutamate, acetylcholine) pathways. We also identify differential expression of ion channel families, including kainite family glutamate receptors, inward-rectifying K(+) (IRK) channels, and transient receptor potential (TRP) A family channels, across central pattern generating tissues. CONCLUSIONS Our transcriptome-wide profiles of the rhythmic pattern generating abdominal and cardiac nervous systems in Homarus americanus reveal candidates for neuronal features that drive the production of motor output in these systems.
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Affiliation(s)
- Lara Lewis McGrath
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA. .,Current address: AstraZeneca, 35 Gatehouse Dr, Waltham, MA, 02451, USA.
| | - Steven V Vollmer
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA.
| | - Stefan T Kaluziak
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA.
| | - Joseph Ayers
- Northeastern University Marine Science Center, 430 Nahant Rd, Nahant, MA, 01908, USA.
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Pulver SR, Bayley TG, Taylor AL, Berni J, Bate M, Hedwig B. Imaging fictive locomotor patterns in larval Drosophila. J Neurophysiol 2015; 114:2564-77. [PMID: 26311188 PMCID: PMC4637366 DOI: 10.1152/jn.00731.2015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/24/2015] [Indexed: 11/22/2022] Open
Abstract
We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca2+ indicators. The Ca2+ signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca2+ signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca2+ signals were normally initiated did not eliminate production of Ca2+ waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques.
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Affiliation(s)
- Stefan R Pulver
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, United Kingdom; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | - Timothy G Bayley
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom; and
| | - Adam L Taylor
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | - Jimena Berni
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom; and
| | - Michael Bate
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom; and
| | - Berthold Hedwig
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom; and
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Jepson JEC, Shahidullah M, Liu D, le Marchand SJ, Liu S, Wu MN, Levitan IB, Dalva MB, Koh K. Regulation of synaptic development and function by the Drosophila PDZ protein Dyschronic. Development 2014; 141:4548-57. [PMID: 25359729 DOI: 10.1242/dev.109538] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Synaptic scaffold proteins control the localization of ion channels and receptors, and facilitate molecular associations between signaling components that modulate synaptic transmission and plasticity. Here, we define novel roles for a recently described scaffold protein, Dsychronic (DYSC), at the Drosophila larval neuromuscular junction. DYSC is the Drosophila homolog of whirlin/DFNB31, a PDZ domain protein linked to Usher syndrome, the most common form of human deaf-blindness. We show that DYSC is expressed presynaptically and is often localized adjacent to the active zone, the site of neurotransmitter release. Loss of DYSC results in marked alterations in synaptic morphology and cytoskeletal organization. Moreover, active zones are frequently enlarged and misshapen in dysc mutants. Electrophysiological analyses further demonstrate that dysc mutants exhibit substantial increases in both evoked and spontaneous synaptic transmission. We have previously shown that DYSC binds to and regulates the expression of the Slowpoke (SLO) BK potassium channel. Consistent with this, slo mutant larvae exhibit similar alterations in synapse morphology, active zone size and neurotransmission, and simultaneous loss of dysc and slo does not enhance these phenotypes, suggesting that dysc and slo act in a common genetic pathway to modulate synaptic development and output. Our data expand our understanding of the neuronal functions of DYSC and uncover non-canonical roles for the SLO potassium channel at Drosophila synapses.
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Affiliation(s)
- James E C Jepson
- Department of Neuroscience, The Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA UCL Institute of Neurology, London WC1N 3BG, UK
| | - Mohammed Shahidullah
- Department of Neuroscience, The Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Die Liu
- Department of Neuroscience, The Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Sylvain J le Marchand
- Department of Neuroscience, The Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Sha Liu
- Department of Neurology, John Hopkins University, Baltimore, MD 21287, USA
| | - Mark N Wu
- Department of Neurology, John Hopkins University, Baltimore, MD 21287, USA
| | - Irwin B Levitan
- Department of Neuroscience, The Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Matthew B Dalva
- Department of Neuroscience, The Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Kyunghee Koh
- Department of Neuroscience, The Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Iyengar A, Wu CF. Flight and seizure motor patterns in Drosophila mutants: simultaneous acoustic and electrophysiological recordings of wing beats and flight muscle activity. J Neurogenet 2014; 28:316-28. [PMID: 25159538 PMCID: PMC5555410 DOI: 10.3109/01677063.2014.957827] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Abstract Tethered flies allow studies of biomechanics and electrophysiology of flight control. We performed microelectrode recordings of spikes in an indirect flight muscle (the dorsal longitudinal muscle, DLMa) coupled with acoustic analysis of wing beat frequency (WBF) via microphone signals. Simultaneous electrophysiological recording of direct and indirect flight muscles has been technically challenging; however, the WBF is thought to reflect in a one-to-one relationship with spiking activity in a subset of direct flight muscles, including muscle m1b. Therefore, our approach enables systematic mutational analysis for changes in temporal features of electrical activity of motor neurons innervating subsets of direct and indirect flight muscles. Here, we report the consequences of specific ion channel disruptions on the spiking activity of myogenic DLMs (firing at ∼5 Hz) and the corresponding WBF (∼200 Hz). We examined mutants of the genes enconding: 1) voltage-gated Ca(2+) channels (cacophony, cac), 2) Ca(2+)-activated K(+) channels (slowpoke, slo), and 3) voltage-gated K(+) channels (Shaker, Sh) and their auxiliary subunits (Hyperkinetic, Hk and quiver, qvr). We found flight initiation in response to an air puff was severely disrupted in both cac and slo mutants. However, once initiated, slo flight was largely unaltered, whereas cac displayed disrupted DLM firing rates and WBF. Sh, Hk, and qvr mutants were able to maintain normal DLM firing rates, despite increased WBF. Notably, defects in the auxiliary subunits encoded by Hk and qvr could lead to distinct consequences, that is, disrupted DLM firing rhythmicity, not observed in Sh. Our mutant analysis of direct and indirect flight muscle activities indicates that the two motor activity patterns may be independently modified by specific ion channel mutations, and that this approach can be extended to other dipteran species and additional motor programs, such as electroconvulsive stimulation-induced seizures.
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Affiliation(s)
- Atulya Iyengar
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Chun-Fang Wu
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
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