1
|
Chen L, Su P, Wang Y, Liu Y, Chen LM, Gao S. CKR-1 orchestrates two motor states from a single motoneuron in C. elegans. iScience 2024; 27:109390. [PMID: 38510145 PMCID: PMC10952047 DOI: 10.1016/j.isci.2024.109390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/22/2023] [Accepted: 02/28/2024] [Indexed: 03/22/2024] Open
Abstract
Neuromodulation is pivotal in modifying neuronal properties and motor states. CKR-1, a homolog of the cholecystokinin receptor, modulates robust escape steering and undulation body bending in C. elegans. Nevertheless, the mechanisms through which CKR-1 governs these motor states remain elusive. We elucidate the head motoneuron SMD as the orchestrator of both motor states. This regulation involves two neuropeptides: NLP-12 from DVA enhances undulation body curvature, while NLP-18 from ASI amplifies Ω-turn head curvature. Moreover, synthetic NLP-12 and NLP-18 peptides elicit CKR-1-dependent currents in Xenopus oocytes and Ca2+ transients in SMD neurons. Notably, CKR-1 shows higher sensitivity to NLP-18 compared to NLP-12. In situ patch-clamp recordings reveal CKR-1, NLP-12, and NLP-18 are not essential for neurotransmission at C. elegans neuromuscular junction, suggesting that SMD independently regulates head and body bending. Our studies illustrate that a single motoneuron SMD utilizes a cholecystokinin receptor CKR-1 to integrate two motor states.
Collapse
Affiliation(s)
- Lili Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Pan Su
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ya Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yuting Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Li-Ming Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| |
Collapse
|
2
|
Istiban MN, De Fruyt N, Kenis S, Beets I. Evolutionary conserved peptide and glycoprotein hormone-like neuroendocrine systems in C. elegans. Mol Cell Endocrinol 2024; 584:112162. [PMID: 38290646 PMCID: PMC11004728 DOI: 10.1016/j.mce.2024.112162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/11/2024] [Accepted: 01/15/2024] [Indexed: 02/01/2024]
Abstract
Peptides and protein hormones form the largest group of secreted signals that mediate intercellular communication and are central regulators of physiology and behavior in all animals. Phylogenetic analyses and biochemical identifications of peptide-receptor systems reveal a broad evolutionary conservation of these signaling systems at the molecular level. Substantial progress has been made in recent years on characterizing the physiological and putative ancestral roles of many peptide systems through comparative studies in invertebrate models. Several peptides and protein hormones are not only molecularly conserved but also have conserved roles across animal phyla. Here, we focus on functional insights gained in the nematode Caenorhabditis elegans that, with its compact and well-described nervous system, provides a powerful model to dissect neuroendocrine signaling networks involved in the control of physiology and behavior. We summarize recent discoveries on the evolutionary conservation and knowledge on the functions of peptide and protein hormone systems in C. elegans.
Collapse
Affiliation(s)
- Majdulin Nabil Istiban
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium
| | - Nathan De Fruyt
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium
| | - Signe Kenis
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium
| | - Isabel Beets
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium.
| |
Collapse
|
3
|
Geng S, Li Q, Zhou X, Zheng J, Liu H, Zeng J, Yang R, Fu H, Hao F, Feng Q, Qi B. Gut commensal E. coli outer membrane proteins activate the host food digestive system through neural-immune communication. Cell Host Microbe 2022; 30:1401-1416.e8. [PMID: 36057258 DOI: 10.1016/j.chom.2022.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/01/2022] [Accepted: 08/05/2022] [Indexed: 12/13/2022]
Abstract
The gastrointestinal tract facilitates food digestion, with the gut microbiota playing pivotal roles in nutrient breakdown and absorption. However, the microbial molecules and downstream signaling pathways that activate food digestion remain unexplored. Here, by establishing a food digestion system in C. elegans, we discover that food breakdown is regulated by the interaction between bacterial outer membrane proteins (OMPs) and a neural-immune pathway. E. coli OmpF/A activate digestion by increasing the neuropeptide NLP-12 that acts on the receptor CCKR. NLP-12 is homologous to mammalian cholecystokinin, known to stimulate dopamine, and we found that loss of dopamine receptors or addition of a dopamine antagonist inhibited OMP-mediated digestion. Dopamine and NLP-12-CKR-1 converge to inhibit PMK-1/p38 innate immune signaling. Moreover, directly inhibiting PMK-1/p38 boosts food digestion. This study uncovers a role of bacterial OMPs in regulating animal nutrient uptake and supports a key role for innate immunity in digestion.
Collapse
Affiliation(s)
- Shengya Geng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Qian Li
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Xue Zhou
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Junkang Zheng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Huimin Liu
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Jie Zeng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Ruizhi Yang
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Herui Fu
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Fanrui Hao
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Qianxu Feng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Bin Qi
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China.
| |
Collapse
|
4
|
Izquierdo PG, Calahorro F, Thisainathan T, Atkins JH, Haszczyn J, Lewis CJ, Tattersall JEH, Green AC, Holden-Dye L, O'Connor V. Cholinergic signaling at the body wall neuromuscular junction distally inhibits feeding behavior in Caenorhabditis elegans. J Biol Chem 2021; 298:101466. [PMID: 34864060 PMCID: PMC8801469 DOI: 10.1016/j.jbc.2021.101466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 11/13/2021] [Accepted: 11/30/2021] [Indexed: 12/27/2022] Open
Abstract
Complex biological functions within organisms are frequently orchestrated by systemic communication between tissues. In the model organism Caenorhabditis elegans, the pharyngeal and body wall neuromuscular junctions are two discrete structures that control feeding and locomotion, respectively. Separate, the well-defined neuromuscular circuits control these distinct tissues. Nonetheless, the emergent behaviors, feeding and locomotion, are coordinated to guarantee the efficiency of food intake. Here, we show that pharmacological hyperactivation of cholinergic transmission at the body wall muscle reduces the rate of pumping behavior. This was evidenced by a systematic screening of the effect of the cholinesterase inhibitor aldicarb on the rate of pharyngeal pumping on food in mutant worms. The screening revealed that the key determinants of the inhibitory effect of aldicarb on pharyngeal pumping are located at the body wall neuromuscular junction. In fact, the selective stimulation of the body wall muscle receptors with the agonist levamisole inhibited pumping in a lev-1-dependent fashion. Interestingly, this response was independent of unc-38, an alpha subunit of the nicotinic receptor classically expressed with lev-1 at the body wall muscle. This implies an uncharacterized lev-1-containing receptor underpins this effect. Overall, our results reveal that body wall cholinergic transmission not only controls locomotion but simultaneously inhibits feeding behavior.
Collapse
Affiliation(s)
- Patricia G Izquierdo
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom.
| | - Fernando Calahorro
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Thibana Thisainathan
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - James H Atkins
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Johanna Haszczyn
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Christian J Lewis
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - John E H Tattersall
- Dstl, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire, United Kingdom
| | - A Christopher Green
- Dstl, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Lindy Holden-Dye
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Vincent O'Connor
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| |
Collapse
|
5
|
Bhat US, Shahi N, Surendran S, Babu K. Neuropeptides and Behaviors: How Small Peptides Regulate Nervous System Function and Behavioral Outputs. Front Mol Neurosci 2021; 14:786471. [PMID: 34924955 PMCID: PMC8674661 DOI: 10.3389/fnmol.2021.786471] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/11/2021] [Indexed: 11/13/2022] Open
Abstract
One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.
Collapse
Affiliation(s)
- Umer Saleem Bhat
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Navneet Shahi
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Siju Surendran
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| |
Collapse
|
6
|
Ramachandran S, Banerjee N, Bhattacharya R, Lemons ML, Florman J, Lambert CM, Touroutine D, Alexander K, Schoofs L, Alkema MJ, Beets I, Francis MM. A conserved neuropeptide system links head and body motor circuits to enable adaptive behavior. eLife 2021; 10:71747. [PMID: 34766905 PMCID: PMC8626090 DOI: 10.7554/elife.71747] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/11/2021] [Indexed: 01/11/2023] Open
Abstract
Neuromodulators promote adaptive behaviors that are often complex and involve concerted activity changes across circuits that are often not physically connected. It is not well understood how neuromodulatory systems accomplish these tasks. Here, we show that the Caenorhabditis elegans NLP-12 neuropeptide system shapes responses to food availability by modulating the activity of head and body wall motor neurons through alternate G-protein coupled receptor (GPCR) targets, CKR-1 and CKR-2. We show ckr-2 deletion reduces body bend depth during movement under basal conditions. We demonstrate CKR-1 is a functional NLP-12 receptor and define its expression in the nervous system. In contrast to basal locomotion, biased CKR-1 GPCR stimulation of head motor neurons promotes turning during local searching. Deletion of ckr-1 reduces head neuron activity and diminishes turning while specific ckr-1 overexpression or head neuron activation promote turning. Thus, our studies suggest locomotor responses to changing food availability are regulated through conditional NLP-12 stimulation of head or body wall motor circuits.
Collapse
Affiliation(s)
- Shankar Ramachandran
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Navonil Banerjee
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Raja Bhattacharya
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Michele L Lemons
- Department of Biological and Physical Sciences, Assumption University, Worcester, United States
| | - Jeremy Florman
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Christopher M Lambert
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Denis Touroutine
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Kellianne Alexander
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Liliane Schoofs
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Mark J Alkema
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| | - Isabel Beets
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, United States
| |
Collapse
|
7
|
Lee J, Magescas J, Fetter RD, Feldman JL, Shen K. Inherited apicobasal polarity defines the key features of axon-dendrite polarity in a sensory neuron. Curr Biol 2021; 31:3768-3783.e3. [PMID: 34270949 DOI: 10.1016/j.cub.2021.06.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 05/05/2021] [Accepted: 06/14/2021] [Indexed: 11/25/2022]
Abstract
Neurons are highly polarized cells with morphologically and functionally distinct dendritic and axonal processes. The molecular mechanisms that establish axon-dendrite polarity in vivo are poorly understood. Here, we describe the initial polarization of posterior deirid (PDE), a ciliated mechanosensory neuron, during development in vivo through 4D live imaging with endogenously tagged proteins. PDE inherits and maintains apicobasal polarity from its epithelial precursor. Its apical domain is directly transformed into the ciliated dendritic tip through apical constriction, which is followed by axonal outgrowth from the opposite basal side of the cell. The apical Par complex and junctional proteins persistently localize at the developing dendritic domain throughout this transition. Consistent with their instructive role in axon-dendrite polarization, conditional depletion of the Par complex and junctional proteins results in robust defects in dendrite and axon formation. During apical constriction, a microtubule-organizing center (MTOC) containing the microtubule nucleator γ-tubulin ring complex (γ-TuRC) forms along the apical junction between PDE and its sister cell in a manner dependent on the Par complex and junctional proteins. This junctional MTOC patterns neuronal microtubule polarity and facilitate the dynein-dependent recruitment of the basal body for ciliogenesis. When non-ciliated neurons are genetically manipulated to obtain ciliated neuronal fate, inherited apicobasal polarity is required for generating ciliated dendritic tips. We propose that inherited apicobasal polarity, together with apical cell-cell interactions drive the morphological and cytoskeletal polarity in early neuronal differentiation.
Collapse
Affiliation(s)
- Joo Lee
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Jérémy Magescas
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Richard D Fetter
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | | | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
8
|
Pandey P, Singh A, Kaur H, Ghosh-Roy A, Babu K. Increased dopaminergic neurotransmission results in ethanol dependent sedative behaviors in Caenorhabditis elegans. PLoS Genet 2021; 17:e1009346. [PMID: 33524034 PMCID: PMC7877767 DOI: 10.1371/journal.pgen.1009346] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 02/11/2021] [Accepted: 01/06/2021] [Indexed: 12/19/2022] Open
Abstract
Ethanol is a widely used drug, excessive consumption of which could lead to medical conditions with diverse symptoms. Ethanol abuse causes dysfunction of memory, attention, speech and locomotion across species. Dopamine signaling plays an essential role in ethanol dependent behaviors in animals ranging from C. elegans to humans. We devised an ethanol dependent assay in which mutants in the dopamine autoreceptor, dop-2, displayed a unique sedative locomotory behavior causing the animals to move in circles while dragging the posterior half of their body. Here, we identify the posterior dopaminergic sensory neuron as being essential to modulate this behavior. We further demonstrate that in dop-2 mutants, ethanol exposure increases dopamine secretion and functions in a DVA interneuron dependent manner. DVA releases the neuropeptide NLP-12 that is known to function through cholinergic motor neurons and affect movement. Thus, DOP-2 modulates dopamine levels at the synapse and regulates alcohol induced movement through NLP-12.
Collapse
Affiliation(s)
- Pratima Pandey
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Anuradha Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Harjot Kaur
- National Brain Research Centre, Gurgaon, India
| | | | - Kavita Babu
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
- Centre for Neuroscience, Indian Institute of Science (IISc), Bangalore, India
| |
Collapse
|
9
|
Morrison M, Fieseler C, Kutz JN. Nonlinear Control in the Nematode C. elegans. Front Comput Neurosci 2021; 14:616639. [PMID: 33551783 PMCID: PMC7862714 DOI: 10.3389/fncom.2020.616639] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/28/2020] [Indexed: 11/26/2022] Open
Abstract
Recent whole-brain calcium imaging recordings of the nematode C. elegans have demonstrated that the neural activity associated with behavior is dominated by dynamics on a low-dimensional manifold that can be clustered according to behavioral states. Previous models of C. elegans dynamics have either been linear models, which cannot support the existence of multiple fixed points in the system, or Markov-switching models, which do not describe how control signals in C. elegans neural dynamics can produce switches between stable states. It remains unclear how a network of neurons can produce fast and slow timescale dynamics that control transitions between stable states in a single model. We propose a global, nonlinear control model which is minimally parameterized and captures the state transitions described by Markov-switching models with a single dynamical system. The model is fit by reproducing the timeseries of the dominant PCA mode in the calcium imaging data. Long and short time-scale changes in transition statistics can be characterized via changes in a single parameter in the control model. Some of these macro-scale transitions have experimental correlates to single neuro-modulators that seem to act as biological controls, allowing this model to generate testable hypotheses about the effect of these neuro-modulators on the global dynamics. The theory provides an elegant characterization of control in the neuron population dynamics in C. elegans. Moreover, the mathematical structure of the nonlinear control framework provides a paradigm that can be generalized to more complex systems with an arbitrary number of behavioral states.
Collapse
Affiliation(s)
- Megan Morrison
- Department of Applied Mathematics, University of Washington, Seattle, WA, United States
| | - Charles Fieseler
- Department of Neurobiology, University of Vienna, Vienna, Austria
| | - J. Nathan Kutz
- Department of Applied Mathematics, University of Washington, Seattle, WA, United States
| |
Collapse
|
10
|
Behavioral and molecular response of the insect parasitic nematode Steinernema carpocapsae to cues emitted by a host, the red palm weevil, Rhynchophorus ferrugineus. Mol Biochem Parasitol 2020; 241:111345. [PMID: 33290763 DOI: 10.1016/j.molbiopara.2020.111345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 11/14/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022]
Abstract
As the larvae of the date palm pest, the red palm weevil, Rhynchophorus ferrugineus, feeds on the host tissue, they emit a distinctive sound which can be recorded outside of the infected tree. We evaluated the response of infective juveniles (IJs) of the entomopathogenic nematodes Steinernema carpocapsae to the R. ferrugineus larvae and it's sound source, separately. In the presence of the insect larvae, 50.2 % of total IJs moved toward those larvae. Recorded insect larvae sound emitted by the speaker resulted in 7% of total IJs near the sound source. RNA-Seq data indicated that more genes were downregulated in S. carpocapsae IJs exposed to insect and speaker compared to non-stimulated IJs. IJs exposed to insect exhibited more up-regulated genes than IJs exposed to speaker. Enriched pathways and biological processes in IJs were similar for both stimuli. The inhibition of locomotion, regulation of neurotransmitter secretion, response to biotic stimulus, and cellular response to chemical stimuli were enriched with unique GO terms for speaker treatment. The regulation of localization, sodium ion transmembrane transport, regulation of response to stress and response to organic substances were the GO categories enriched unique to insect. The host-parasitic interaction was regulated by the differential expression of Ras/MAP kinase, TGF-beta signaling, insulin signaling, AMPK signaling, PPAR signaling pathways and many developmental pathways. More prominent R. ferrugineus host localization by S. carpocapsae was primarily due to the differential transcriptional regulation of olfactory signal transduction, FOXO-family proteins, calcium signaling, WNT and mTOR signaling pathway. The neural basis for the nematode attraction to insect host is based on the chemosensation and the mechanosensation. Many neuropeptides and neuromodulators are involved in regulating the foraging behavior of S. carpocapsae. The results of this study provide new insights into the molecular mechanisms that allow these nematodes to seek insect hosts. Our finding, especially the molecular ones suggest that chemical cues emitted by the active insect host are stimulants of nematodes attraction. Whereas the sound emitted by the insect has minor effects on the nematode behavior.
Collapse
|
11
|
Lipton DM, Maeder CI, Shen K. Rapid Assembly of Presynaptic Materials behind the Growth Cone in Dopaminergic Neurons Is Mediated by Precise Regulation of Axonal Transport. Cell Rep 2019; 24:2709-2722. [PMID: 30184504 PMCID: PMC6179448 DOI: 10.1016/j.celrep.2018.07.096] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 06/21/2018] [Accepted: 07/27/2018] [Indexed: 11/15/2022] Open
Abstract
The proper assembly of neural circuits depends on the process of synaptogenesis, or the formation of synapses between partner neurons. Using the dopaminergic PDE neurons in C. elegans, we developed an in vivo system to study the earliest steps of the formation of en passant presynaptic specializations behind an extending growth cone. We find that presynaptic materials coalesce into puncta in as little as a few minutes and that both synaptic vesicle (SV) and active zone (AZ) proteins arrive nearly simultaneously at the nascent sites of synapse formation. We show that precise regulation of UNC-104/Kinesin-3 determines the distribution of SV proteins along the axon. The localization of AZ proteins to en passant puncta, however, is largely independent of the major axonal kinesins: UNC-104/Kinesin-3 and UNC-116/ Kinesin-1. Moreover, AZ proteins play a crucial role in recruiting and tethering SV precursors (SVPs). Lipton et al. explore the initial steps of synapse formation in vivo. They find that clustering of major presynaptic material occurs extremely rapidly (<5 min). Both synaptic vesicle precursors and active zone proteins accumulate simultaneously at developing puncta. Precise regulation of the Kinesin-3 activation state strongly influences the positioning of vesicles along the axon during development.
Collapse
Affiliation(s)
- David M Lipton
- Howard Hughes Medical Institute, Department of Biology, Stanford University, 385 Serra Mall, Stanford, CA 94305, USA; Neurosciences Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Celine I Maeder
- Howard Hughes Medical Institute, Department of Biology, Stanford University, 385 Serra Mall, Stanford, CA 94305, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, 385 Serra Mall, Stanford, CA 94305, USA.
| |
Collapse
|
12
|
Tao L, Porto D, Li Z, Fechner S, Lee SA, Goodman MB, Xu XZS, Lu H, Shen K. Parallel Processing of Two Mechanosensory Modalities by a Single Neuron in C. elegans. Dev Cell 2019; 51:617-631.e3. [PMID: 31735664 DOI: 10.1016/j.devcel.2019.10.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 05/24/2019] [Accepted: 10/14/2019] [Indexed: 10/25/2022]
Abstract
Neurons convert synaptic or sensory inputs into cellular outputs. It is not well understood how a single neuron senses, processes multiple stimuli, and generates distinct neuronal outcomes. Here, we describe the mechanism by which the C. elegans PVD neurons sense two mechanical stimuli: external touch and proprioceptive body movement. These two stimuli are detected by distinct mechanosensitive DEG/ENaC/ASIC channels, which trigger distinct cellular outputs linked to mechanonociception and proprioception. Mechanonociception depends on DEGT-1 and activates PVD's downstream command interneurons through its axon, while proprioception depends on DEL-1, UNC-8, and MEC-10 to induce local dendritic Ca2+ increase and dendritic release of a neuropeptide NLP-12. NLP-12 directly modulates neuromuscular junction activity through the cholecystokinin receptor homolog on motor axons, setting muscle tone and movement vigor. Thus, the same neuron simultaneously uses both its axon and dendrites as output apparatus to drive distinct sensorimotor outcomes.
Collapse
Affiliation(s)
- Li Tao
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Daniel Porto
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Zhaoyu Li
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sylvia Fechner
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Sol Ah Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Miriam B Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - X Z Shawn Xu
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA.
| |
Collapse
|
13
|
Integrins Have Cell-Type-Specific Roles in the Development of Motor Neuron Connectivity. J Dev Biol 2019; 7:jdb7030017. [PMID: 31461926 PMCID: PMC6787651 DOI: 10.3390/jdb7030017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/11/2019] [Accepted: 08/22/2019] [Indexed: 01/16/2023] Open
Abstract
Formation of the nervous system requires a complex series of events including proper extension and guidance of neuronal axons and dendrites. Here we investigate the requirement for integrins, a class of transmembrane cell adhesion receptors, in regulating these processes across classes of C. elegans motor neurons. We show α integrin/ina-1 is expressed by both GABAergic and cholinergic motor neurons. Despite this, our analysis of hypomorphic ina-1(gm144) mutants indicates preferential involvement of α integrin/ina-1 in GABAergic commissural development, without obvious involvement in cholinergic commissural development. The defects in GABAergic commissures of ina-1(gm144) mutants included both premature termination and guidance errors and were reversed by expression of wild type ina-1 under control of the native ina-1 promoter. Our results also show that α integrin/ina-1 is important for proper outgrowth and guidance of commissures from both embryonic and post-embryonic born GABAergic motor neurons, indicating an ongoing requirement for integrin through two phases of GABAergic neuron development. Our findings provide insights into neuron-specific roles for integrin that would not be predicted based solely upon expression analysis.
Collapse
|
14
|
Huang YC, Pirri JK, Rayes D, Gao S, Mulcahy B, Grant J, Saheki Y, Francis MM, Zhen M, Alkema MJ. Gain-of-function mutations in the UNC-2/CaV2α channel lead to excitation-dominant synaptic transmission in Caenorhabditis elegans. eLife 2019; 8:e45905. [PMID: 31364988 PMCID: PMC6713474 DOI: 10.7554/elife.45905] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 07/30/2019] [Indexed: 01/17/2023] Open
Abstract
Mutations in pre-synaptic voltage-gated calcium channels can lead to familial hemiplegic migraine type 1 (FHM1). While mammalian studies indicate that the migraine brain is hyperexcitable due to enhanced excitation or reduced inhibition, the molecular and cellular mechanisms underlying this excitatory/inhibitory (E/I) imbalance are poorly understood. We identified a gain-of-function (gf) mutation in the Caenorhabditis elegans CaV2 channel α1 subunit, UNC-2, which leads to increased calcium currents. unc-2(zf35gf) mutants exhibit hyperactivity and seizure-like motor behaviors. Expression of the unc-2 gene with FHM1 substitutions R192Q and S218L leads to hyperactivity similar to that of unc-2(zf35gf) mutants. unc-2(zf35gf) mutants display increased cholinergic and decreased GABAergic transmission. Moreover, increased cholinergic transmission in unc-2(zf35gf) mutants leads to an increase of cholinergic synapses and a TAX-6/calcineurin-dependent reduction of GABA synapses. Our studies reveal mechanisms through which CaV2 gain-of-function mutations disrupt excitation-inhibition balance in the nervous system.
Collapse
Affiliation(s)
- Yung-Chi Huang
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Jennifer K Pirri
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Diego Rayes
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Shangbang Gao
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Jeff Grant
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Yasunori Saheki
- Lulu and Anthony Wang Laboratory of Neural Circuits and BehaviorThe Rockefeller UniversityNew YorkUnited States
| | - Michael M Francis
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Mark J Alkema
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| |
Collapse
|
15
|
Griffin EF, Scopel SE, Stephen CA, Holzhauer AC, Vaji MA, Tuckey RA, Berkowitz LA, Caldwell KA, Caldwell GA. ApoE-associated modulation of neuroprotection from Aβ-mediated neurodegeneration in transgenic Caenorhabditis elegans. Dis Model Mech 2019; 12:dmm.037218. [PMID: 30683808 PMCID: PMC6398492 DOI: 10.1242/dmm.037218] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/17/2019] [Indexed: 12/13/2022] Open
Abstract
Allele-specific distinctions in the human apolipoprotein E (APOE) locus represent the best-characterized genetic predictor of Alzheimer's disease (AD) risk. Expression of isoform APOEε2 is associated with reduced risk, while APOEε3 is neutral and APOEε4 carriers exhibit increased susceptibility. Using Caenorhabditis elegans, we generated a novel suite of humanized transgenic nematodes to facilitate neuronal modeling of amyloid-beta peptide (Aβ) co-expression in the context of distinct human APOE alleles. We found that co-expression of human APOEε2 with Aβ attenuated Aβ-induced neurodegeneration, whereas expression of the APOEε4 allele had no effect on neurodegeneration, indicating a loss of neuroprotective capacity. Notably, the APOEε3 allele displayed an intermediate phenotype; it was not neuroprotective in young adults but attenuated neurodegeneration in older animals. There was no functional impact from the three APOE isoforms in the absence of Aβ co-expression. Pharmacological treatment that examined neuroprotective effects of APOE alleles on calcium homeostasis showed allele-specific responses to changes in ER-associated calcium dynamics in the Aβ background. Additionally, Aβ suppressed survival, an effect that was rescued by APOEε2 and APOEε3, but not APOEε4. Expression of the APOE alleles in neurons, independent of Aβ, exerted no impact on survival. Taken together, these results illustrate that C. elegans provides a powerful in vivo platform with which to explore how AD-associated neuronal pathways are modulated by distinct APOE gene products in the context of Aβ-associated neurotoxicity. The significance of both ApoE and Aβ to AD highlights the utility of this new pre-clinical model as a means to dissect their functional inter-relationship.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Edward F Griffin
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
| | - Samuel E Scopel
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
| | - Cayman A Stephen
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
| | - Adam C Holzhauer
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
| | - Madeline A Vaji
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
| | - Ryan A Tuckey
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
| | - Laura A Berkowitz
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
| | - Kim A Caldwell
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA.,Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Nathan Shock Center for Research on the Basic Biology of Aging, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Guy A Caldwell
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA .,Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Nathan Shock Center for Research on the Basic Biology of Aging, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| |
Collapse
|
16
|
Svensson E, Apergis-Schoute J, Burnstock G, Nusbaum MP, Parker D, Schiöth HB. General Principles of Neuronal Co-transmission: Insights From Multiple Model Systems. Front Neural Circuits 2019; 12:117. [PMID: 30728768 PMCID: PMC6352749 DOI: 10.3389/fncir.2018.00117] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 12/14/2018] [Indexed: 12/22/2022] Open
Abstract
It is now accepted that neurons contain and release multiple transmitter substances. However, we still have only limited insight into the regulation and functional effects of this co-transmission. Given that there are 200 or more neurotransmitters, the chemical complexity of the nervous system is daunting. This is made more-so by the fact that their interacting effects can generate diverse non-linear and novel consequences. The relatively poor history of pharmacological approaches likely reflects the fact that manipulating a transmitter system will not necessarily mimic its roles within the normal chemical environment of the nervous system (e.g., when it acts in parallel with co-transmitters). In this article, co-transmission is discussed in a range of systems [from invertebrate and lower vertebrate models, up to the mammalian peripheral and central nervous system (CNS)] to highlight approaches used, degree of understanding, and open questions and future directions. Finally, we offer some outlines of what we consider to be the general principles of co-transmission, as well as what we think are the most pressing general aspects that need to be addressed to move forward in our understanding of co-transmission.
Collapse
Affiliation(s)
- Erik Svensson
- BMC, Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden
| | - John Apergis-Schoute
- Department of Neurosciences, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Geoffrey Burnstock
- Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, VIC, Australia
| | - Michael P Nusbaum
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - David Parker
- Department of Physiology, Development and Neuroscience, Faculty of Biology, University of Cambridge, Cambridge, United Kingdom
| | - Helgi B Schiöth
- BMC, Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden.,Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russia
| |
Collapse
|
17
|
Koelle MR. Neurotransmitter signaling through heterotrimeric G proteins: insights from studies in C. elegans. WORMBOOK : THE ONLINE REVIEW OF C. ELEGANS BIOLOGY 2018; 2018:1-52. [PMID: 26937633 PMCID: PMC5010795 DOI: 10.1895/wormbook.1.75.2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neurotransmitters signal via G protein coupled receptors (GPCRs) to modulate activity of neurons and muscles. C. elegans has ∼150 G protein coupled neuropeptide receptor homologs and 28 additional GPCRs for small-molecule neurotransmitters. Genetic studies in C. elegans demonstrate that neurotransmitters diffuse far from their release sites to activate GPCRs on distant cells. Individual receptor types are expressed on limited numbers of cells and thus can provide very specific regulation of an individual neural circuit and behavior. G protein coupled neurotransmitter receptors signal principally via the three types of heterotrimeric G proteins defined by the G alpha subunits Gαo, Gαq, and Gαs. Each of these G alpha proteins is found in all neurons plus some muscles. Gαo and Gαq signaling inhibit and activate neurotransmitter release, respectively. Gαs signaling, like Gαq signaling, promotes neurotransmitter release. Many details of the signaling mechanisms downstream of Gαq and Gαs have been delineated and are consistent with those of their mammalian orthologs. The details of the signaling mechanism downstream of Gαo remain a mystery. Forward genetic screens in C. elegans have identified new molecular components of neural G protein signaling mechanisms, including Regulators of G protein Signaling (RGS proteins) that inhibit signaling, a new Gαq effector (the Trio RhoGEF domain), and the RIC-8 protein that is required for neuronal Gα signaling. A model is presented in which G proteins sum up the variety of neuromodulator signals that impinge on a neuron to calculate its appropriate output level.
Collapse
Affiliation(s)
- Michael R Koelle
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven CT 06520 USA
| |
Collapse
|
18
|
Oranth A, Schultheis C, Tolstenkov O, Erbguth K, Nagpal J, Hain D, Brauner M, Wabnig S, Steuer Costa W, McWhirter RD, Zels S, Palumbos S, Miller III DM, Beets I, Gottschalk A. Food Sensation Modulates Locomotion by Dopamine and Neuropeptide Signaling in a Distributed Neuronal Network. Neuron 2018; 100:1414-1428.e10. [DOI: 10.1016/j.neuron.2018.10.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 09/14/2018] [Accepted: 10/12/2018] [Indexed: 01/02/2023]
|
19
|
Morrison LM, Edwards SL, Manning L, Stec N, Richmond JE, Miller KG. Sentryn and SAD Kinase Link the Guided Transport and Capture of Dense Core Vesicles in Caenorhabditis elegans. Genetics 2018; 210:925-946. [PMID: 30401764 PMCID: PMC6218223 DOI: 10.1534/genetics.118.300847] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
Dense core vesicles (DCVs) can transmit signals by releasing neuropeptides from specialized synaptic regions called active zones. DCVs reach the active zone by motorized transport through a long axon. A reverse motor frequently interrupts progress by taking DCVs in the opposite direction. "Guided transport" refers to the mechanism by which outward movements ultimately dominate to bring DCVs to the synaptic region. After guided transport, DCVs alter their interactions with motors and enter a "captured" state. The mechanisms of guided transport and capture of DCVs are unknown. Here, we discovered two proteins that contribute to both processes in Caenorhabditis elegans SAD kinase and a novel conserved protein we named Sentryn are the first proteins found to promote DCV capture. By imaging DCVs moving in various regions of single identified neurons in living animals, we found that DCV guided transport and capture are linked through SAD kinase, Sentryn, and Liprin-α. These proteins act together to regulate DCV motorized transport in a region-specific manner. Between the cell body and the synaptic region, they promote forward transport. In the synaptic region, where all three proteins are highly enriched at active zones, they promote DCV pausing by inhibiting transport in both directions. These three proteins appear to be part of a special subset of active zone-enriched proteins because other active zone proteins do not share their unique functions.
Collapse
Affiliation(s)
- Logan M Morrison
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
| | - Stacey L Edwards
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
| | - Laura Manning
- Department of Biological Sciences, University of Illinois at Chicago, Illinois 60607
| | - Natalia Stec
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
| | - Janet E Richmond
- Department of Biological Sciences, University of Illinois at Chicago, Illinois 60607
| | - Kenneth G Miller
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
| |
Collapse
|
20
|
Essmann CL, Ryan KR, Elmi M, Bryon-Dodd K, Porter A, Vaughan A, McMullan R, Nurrish S. Activation of RHO-1 in cholinergic motor neurons competes with dopamine signalling to control locomotion. PLoS One 2018; 13:e0204057. [PMID: 30240421 PMCID: PMC6150489 DOI: 10.1371/journal.pone.0204057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 08/31/2018] [Indexed: 12/14/2022] Open
Abstract
The small GTPase RhoA plays a crucial role in the regulation of neuronal signalling to generate behaviour. In the developing nervous system RhoA is known to regulate the actin cytoskeleton, however the effectors of RhoA-signalling in adult neurons remain largely unidentified. We have previously shown that activation of the RhoA ortholog (RHO-1) in C. elegans cholinergic motor neurons triggers hyperactivity of these neurons and loopy locomotion with exaggerated body bends. This is achieved in part through increased diacylglycerol (DAG) levels and the recruitment of the synaptic vesicle protein UNC-13 to synaptic release sites, however other pathways remain to be identified. Dopamine, which is negatively regulated by the dopamine re-uptake transporter (DAT), has a central role in modulating locomotion in both humans and C. elegans. In this study we identify a new pathway in which RHO-1 regulates locomotory behaviour by repressing dopamine signalling, via DAT-1, linking these two pathways together. We observed an upregulation of dat-1 expression when RHO-1 is activated and show that loss of DAT-1 inhibits the loopy locomotion phenotype caused by RHO-1 activation. Reducing dopamine signalling in dat-1 mutants through mutations in genes involved in dopamine synthesis or in the dopamine receptor DOP-1 restores the ability of RHO-1 to trigger loopy locomotion in dat-1 mutants. Taken together, we show that negative regulation of dopamine signalling via DAT-1 is necessary for the neuronal RHO-1 pathway to regulate locomotion.
Collapse
Affiliation(s)
- Clara L. Essmann
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Katie R. Ryan
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Muna Elmi
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Kimberley Bryon-Dodd
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Andrew Porter
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Andrew Vaughan
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Rachel McMullan
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Stephen Nurrish
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| |
Collapse
|
21
|
Philbrook A, Ramachandran S, Lambert CM, Oliver D, Florman J, Alkema MJ, Lemons M, Francis MM. Neurexin directs partner-specific synaptic connectivity in C. elegans. eLife 2018; 7:35692. [PMID: 30039797 PMCID: PMC6057746 DOI: 10.7554/elife.35692] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/21/2018] [Indexed: 01/14/2023] Open
Abstract
In neural circuits, individual neurons often make projections onto multiple postsynaptic partners. Here, we investigate molecular mechanisms by which these divergent connections are generated, using dyadic synapses in C. elegans as a model. We report that C. elegans nrx-1/neurexin directs divergent connectivity through differential actions at synapses with partnering neurons and muscles. We show that cholinergic outputs onto neurons are, unexpectedly, located at previously undefined spine-like protrusions from GABAergic dendrites. Both these spine-like features and cholinergic receptor clustering are strikingly disrupted in the absence of nrx-1. Excitatory transmission onto GABAergic neurons, but not neuromuscular transmission, is also disrupted. Our data indicate that NRX-1 located at presynaptic sites specifically directs postsynaptic development in GABAergic neurons. Our findings provide evidence that individual neurons can direct differential patterns of connectivity with their post-synaptic partners through partner-specific utilization of synaptic organizers, offering a novel view into molecular control of divergent connectivity. Nervous systems are complex networks of interconnected cells called neurons. These networks vary in size from a few hundred cells in worms, to tens of billions in the human brain. Within these networks, each individual neuron forms connections – called synapses – with many others. But these partner neurons are not necessarily alike. In fact, they may be different cell types. How neurons form distinct connections with different partner cells remains unclear. Part of the answer may lie in specialized proteins called cell adhesion molecules. These proteins occur on the cell surface and enable neurons to recognize one another. This helps ensure that the cells form appropriate connections via synapses. Cell adhesion molecules are therefore also known as synaptic organizers. Philbrook et al. have now examined the role of synaptic organizers in wiring up the nervous system of the nematode worm and model organism Caenorhabditis elegans. Motor neurons form connections with two types of partner cell: muscle cells and neurons. Philbrook et al. screened C. elegans that have mutations in genes encoding various synaptic organizers. This revealed that a protein called neurexin must be present for motor neurons to form synapses with other neurons. By contrast, neurexin is not required for the same neurons to establish synapses with muscles. Philbrook et al. found that neuron-to-neuron synapses arise at specialized finger-like projections. These resemble the dendritic spines at which synapses form in the brains of mammals, and had not been previously identified in C. elegans. In worms that lack neurexin, these spine-like structures do not form correctly, disrupting the formation of neuron-to-neuron connections. Previous work has implicated neurexin in synapse formation in the mammalian brain. But this is the first study to reveal a role for neurexin in establishing partner-specific synaptic connections. Mutations in synaptic organizers, including neurexin, contribute to disorders of brain development. These include schizophrenia and autism spectrum disorders. Learning more about how neurexin helps establish specific synaptic connections may help us understand how these disorders arise.
Collapse
Affiliation(s)
- Alison Philbrook
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Shankar Ramachandran
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Christopher M Lambert
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Devyn Oliver
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Jeremy Florman
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Mark J Alkema
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Michele Lemons
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States.,Department of Natural Sciences, Assumption College, Worcester, United States
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| |
Collapse
|
22
|
Clark T, Hapiak V, Oakes M, Mills H, Komuniecki R. Monoamines differentially modulate neuropeptide release from distinct sites within a single neuron pair. PLoS One 2018; 13:e0196954. [PMID: 29723289 PMCID: PMC5933757 DOI: 10.1371/journal.pone.0196954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/23/2018] [Indexed: 12/14/2022] Open
Abstract
Monoamines and neuropeptides often modulate the same behavior, but monoaminergic-peptidergic crosstalk remains poorly understood. In Caenorhabditis elegans, the adrenergic-like ligands, tyramine (TA) and octopamine (OA) require distinct subsets of neuropeptides in the two ASI sensory neurons to inhibit nociception. TA selectively increases the release of ASI neuropeptides encoded by nlp-14 or nlp-18 from either synaptic/perisynaptic regions of ASI axons or the ASI soma, respectively, and OA selectively increases the release of ASI neuropeptides encoded by nlp-9 asymmetrically, from only the synaptic/perisynaptic region of the right ASI axon. The predicted amino acid preprosequences of genes encoding either TA- or OA-dependent neuropeptides differed markedly. However, these distinct preprosequences were not sufficient to confer monoamine-specificity and additional N-terminal peptide-encoding sequence was required. Collectively, our results demonstrate that TA and OA specifically and differentially modulate the release of distinct subsets of neuropeptides from different subcellular sites within the ASIs, highlighting the complexity of monoaminergic/peptidergic modulation, even in animals with a relatively simple nervous system.
Collapse
Affiliation(s)
- Tobias Clark
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Vera Hapiak
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Mitchell Oakes
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Holly Mills
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Richard Komuniecki
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
- * E-mail:
| |
Collapse
|
23
|
Gao S, Guan SA, Fouad AD, Meng J, Kawano T, Huang YC, Li Y, Alcaire S, Hung W, Lu Y, Qi YB, Jin Y, Alkema M, Fang-Yen C, Zhen M. Excitatory motor neurons are local oscillators for backward locomotion. eLife 2018; 7:e29915. [PMID: 29360035 PMCID: PMC5780044 DOI: 10.7554/elife.29915] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/22/2017] [Indexed: 01/16/2023] Open
Abstract
Cell- or network-driven oscillators underlie motor rhythmicity. The identity of C. elegans oscillators remains unknown. Through cell ablation, electrophysiology, and calcium imaging, we show: (1) forward and backward locomotion is driven by different oscillators; (2) the cholinergic and excitatory A-class motor neurons exhibit intrinsic and oscillatory activity that is sufficient to drive backward locomotion in the absence of premotor interneurons; (3) the UNC-2 P/Q/N high-voltage-activated calcium current underlies A motor neuron's oscillation; (4) descending premotor interneurons AVA, via an evolutionarily conserved, mixed gap junction and chemical synapse configuration, exert state-dependent inhibition and potentiation of A motor neuron's intrinsic activity to regulate backward locomotion. Thus, motor neurons themselves derive rhythms, which are dually regulated by the descending interneurons to control the reversal motor state. These and previous findings exemplify compression: essential circuit properties are conserved but executed by fewer numbers and layers of neurons in a small locomotor network.
Collapse
Affiliation(s)
- Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of EducationCollege of Life Science and Technology, Huazhong University of Science and TechnologyWuhanChina
| | - Sihui Asuka Guan
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Anthony D Fouad
- Department of BioengineeringSchool of Engineering and Applied Science, University of PennsylvaniaPhiladelphiaUnited States
| | - Jun Meng
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Taizo Kawano
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Yung-Chi Huang
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Yi Li
- Key Laboratory of Molecular Biophysics of the Ministry of EducationCollege of Life Science and Technology, Huazhong University of Science and TechnologyWuhanChina
| | - Salvador Alcaire
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Yangning Lu
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Yingchuan Billy Qi
- Neurobiology Section, Division of Biological SciencesUniversity of CaliforniaSan DiegoUnited States
| | - Yishi Jin
- Neurobiology Section, Division of Biological SciencesUniversity of CaliforniaSan DiegoUnited States
| | - Mark Alkema
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Christopher Fang-Yen
- Department of BioengineeringSchool of Engineering and Applied Science, University of PennsylvaniaPhiladelphiaUnited States
- Department of NeuroscienceUniversity of PennsylvaniaPhiladelphiaUnited States
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| |
Collapse
|
24
|
Jiang HN, Li Y, Jiang WY, Cui ZJ. Cholecystokinin 1 Receptor - A Unique G Protein- Coupled Receptor Activated by Singlet Oxygen ( GPCR-ABSO). Front Physiol 2018; 9:497. [PMID: 29867546 PMCID: PMC5953346 DOI: 10.3389/fphys.2018.00497] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/18/2018] [Indexed: 02/05/2023] Open
Abstract
Plasma membrane-delimited generation of singlet oxygen by photodynamic action with photosensitizer sulfonated aluminum phthalocyanine (SALPC) activates cholecystokinin 1 receptor (CCK1R) in pancreatic acini. Whether CCK1R retains such photooxidative singlet oxygen activation properties in other environments is not known. Genetically encoded protein photosensitizers KillerRed or mini singlet oxygen generator (miniSOG) were expressed in pancreatic acinar tumor cell line AR4-2J, CCK1R, KillerRed or miniSOG were expressed in HEK293 or CHO-K1 cells. Cold light irradiation (87 mW⋅cm-2) was applied to photosensitizer-expressing cells to examine photodynamic activation of CCK1R by Fura-2 fluorescent calcium imaging. When CCK1R was transduced into HEK293 cells which lack endogenous CCK1R, photodynamic action with SALPC was found to activate CCK1R in CCK1R-HEK293 cells. When KillerRed or miniSOG were transduced into AR4-2J which expresses endogenous CCK1R, KillerRed or miniSOG photodynamic action at the plasma membrane also activated CCK1R. When fused KillerRed-CCK1R was transduced into CHO-K1 cells, light irradiation activated the fused CCK1R leading to calcium oscillations. Therefore KillerRed either expressed independently, or fused with CCK1R can both activate CCK1R photodynamically. It is concluded that photodynamic singlet oxygen activation is an intrinsic property of CCK1R, independent of photosensitizer used, or CCK1R-expressing cell types. Photodynamic singlet oxygen CCK1R activation after transduction of genetically encoded photosensitizer in situ may provide a convenient way to verify intrinsic physiological functions of CCK1R in multiple CCK1R-expressing cells and tissues, or to actuate CCK1R function in CCK1R-expressing and non-expressing cell types after transduction with fused KillerRed-CCK1R.
Collapse
|
25
|
Barbagallo B, Philbrook A, Touroutine D, Banerjee N, Oliver D, Lambert CM, Francis MM. Excitatory neurons sculpt GABAergic neuronal connectivity in the C. elegans motor circuit. Development 2017; 144:1807-1819. [PMID: 28420711 DOI: 10.1242/dev.141911] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 04/03/2017] [Indexed: 11/20/2022]
Abstract
Establishing and maintaining the appropriate number of GABA synapses is key for balancing excitation and inhibition in the nervous system, though we have only a limited understanding of the mechanisms controlling GABA circuit connectivity. Here, we show that disrupting cholinergic innervation of GABAergic neurons in the C. elegans motor circuit alters GABAergic neuron synaptic connectivity. These changes are accompanied by reduced frequency and increased amplitude of GABAergic synaptic events. Acute genetic disruption in early development, during the integration of post-embryonic-born GABAergic neurons into the circuit, produces irreversible effects on GABAergic synaptic connectivity that mimic those produced by chronic manipulations. In contrast, acute genetic disruption of cholinergic signaling in the adult circuit does not reproduce these effects. Our findings reveal that GABAergic signaling is regulated by cholinergic neuronal activity, probably through distinct mechanisms in the developing and mature nervous system.
Collapse
Affiliation(s)
- Belinda Barbagallo
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Alison Philbrook
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Denis Touroutine
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Navonil Banerjee
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Devyn Oliver
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Christopher M Lambert
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| |
Collapse
|
26
|
Banerjee N, Bhattacharya R, Gorczyca M, Collins KM, Francis MM. Local neuropeptide signaling modulates serotonergic transmission to shape the temporal organization of C. elegans egg-laying behavior. PLoS Genet 2017; 13:e1006697. [PMID: 28384151 PMCID: PMC5398689 DOI: 10.1371/journal.pgen.1006697] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/20/2017] [Accepted: 03/15/2017] [Indexed: 11/18/2022] Open
Abstract
Animal behaviors are often composed of distinct alternating behavioral states. Neuromodulatory signals are thought to be critical for establishing stable behavioral states and for orchestrating transitions between them. However, we have only a limited understanding of how neuromodulatory systems act in vivo to alter circuit performance and shape behavior. To address these questions, we have investigated neuromodulatory signaling in the context of Caenorhabditis elegans egg-laying. Egg-laying activity cycles between discrete states-short bursts of egg deposition (active phases) that alternate with prolonged quiescent periods (inactive phases). Here using genetic, pharmacological and optogenetic approaches for cell-specific activation and inhibition, we show that a group of neurosecretory cells (uv1) located in close spatial proximity to the egg-laying neuromusculature direct the temporal organization of egg-laying by prolonging the duration of inactive phases. We demonstrate that the modulatory effects of the uv1 cells are mediated by peptides encoded by the nlp-7 and flp-11 genes that act locally to inhibit circuit activity, primarily by inhibiting vesicular release of serotonin from HSN motor neurons. This peptidergic inhibition is achieved, at least in part, by reducing synaptic vesicle abundance in the HSN motor neurons. By linking the in vivo actions of specific neuropeptide signaling systems with the generation of stable behavioral outcomes, our study reveals how cycles of neuromodulation emanating from non-neuronal cells can fundamentally shape the organization of a behavioral program.
Collapse
Affiliation(s)
- Navonil Banerjee
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
| | - Raja Bhattacharya
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
| | - Michael Gorczyca
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
| | - Kevin M. Collins
- Department of Biology, University of Miami, Coral Gables, FL United States of America
| | - Michael M. Francis
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
| |
Collapse
|
27
|
Locomotion Behavior Is Affected by the Gα S Pathway and the Two-Pore-Domain K + Channel TWK-7 Interacting in GABAergic Motor Neurons in Caenorhabditis elegans. Genetics 2017; 206:283-297. [PMID: 28341653 DOI: 10.1534/genetics.116.195669] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/19/2017] [Indexed: 01/03/2023] Open
Abstract
Adjusting the efficiency of movement in response to environmental cues is an essential integrative characteristic of adaptive locomotion behavior across species. However, the modulatory molecules and the pathways involved are largely unknown. Recently, we demonstrated that in Caenorhabditis elegans, a loss-of-function of the two-pore-domain potassium (K2P) channel TWK-7 causes a fast, coordinated, and persistent forward crawling behavior in which five central aspects of stimulated locomotion-velocity, direction, wave parameters, duration, and straightness-are affected. Here, we isolated the reduction-of-function allele cau1 of the C. elegans gene kin-2 in a forward genetic screen and showed that it phenocopies the locomotor activity and locomotion behavior of twk-7(null) animals. Kin-2 encodes the negative regulatory subunit of protein kinase A (KIN-1/PKA). Consistently, we found that other gain-of-function mutants of the GαS-KIN-1/PKA pathway resemble kin-2(cau1) and twk-7(null) in locomotion phenotype. Using the powerful genetics of the C. elegans system in combination with cell type-specific approaches and detailed locomotion analyses, we identified TWK-7 as a putative downstream target of the GαS-KIN-1/PKA pathway at the level of the γ-aminobutyric acid (GABA)ergic D-type motor neurons. Due to this epistatic interaction, we suggest that KIN-1/PKA and TWK-7 may share a common pathway that is probably involved in the modulation of both locomotor activity and locomotion behavior during forward crawling.
Collapse
|
28
|
Bentley B, Branicky R, Barnes CL, Chew YL, Yemini E, Bullmore ET, Vértes PE, Schafer WR. The Multilayer Connectome of Caenorhabditis elegans. PLoS Comput Biol 2016; 12:e1005283. [PMID: 27984591 PMCID: PMC5215746 DOI: 10.1371/journal.pcbi.1005283] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 01/04/2017] [Accepted: 12/05/2016] [Indexed: 11/17/2022] Open
Abstract
Connectomics has focused primarily on the mapping of synaptic links in the brain; yet it is well established that extrasynaptic volume transmission, especially via monoamines and neuropeptides, is also critical to brain function and occurs primarily outside the synaptic connectome. We have mapped the putative monoamine connections, as well as a subset of neuropeptide connections, in C. elegans based on new and published gene expression data. The monoamine and neuropeptide networks exhibit distinct topological properties, with the monoamine network displaying a highly disassortative star-like structure with a rich-club of interconnected broadcasting hubs, and the neuropeptide network showing a more recurrent, highly clustered topology. Despite the low degree of overlap between the extrasynaptic (or wireless) and synaptic (or wired) connectomes, we find highly significant multilink motifs of interaction, pinpointing locations in the network where aminergic and neuropeptide signalling modulate synaptic activity. Thus, the C. elegans connectome can be mapped as a multiplex network with synaptic, gap junction, and neuromodulator layers representing alternative modes of interaction between neurons. This provides a new topological plan for understanding how aminergic and peptidergic modulation of behaviour is achieved by specific motifs and loci of integration between hard-wired synaptic or junctional circuits and extrasynaptic signals wirelessly broadcast from a small number of modulatory neurons.
Collapse
Affiliation(s)
- Barry Bentley
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Robyn Branicky
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Christopher L. Barnes
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
- HHMI Janelia Research Campus, Ashburn, VA, United States of America
| | - Yee Lian Chew
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Eviatar Yemini
- Department of Biological Sciences, Columbia University, New York, NY, United States of America
| | - Edward T. Bullmore
- Department of Psychiatry, University of Cambridge, Cambridge United Kingdom
- ImmunoPsychiatry, Alternative Discovery & Development, GlaxoSmithKline R&D, Cambridge United Kingdom
| | - Petra E. Vértes
- Department of Psychiatry, University of Cambridge, Cambridge United Kingdom
| | - William R. Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| |
Collapse
|
29
|
Lim MA, Chitturi J, Laskova V, Meng J, Findeis D, Wiekenberg A, Mulcahy B, Luo L, Li Y, Lu Y, Hung W, Qu Y, Ho CY, Holmyard D, Ji N, McWhirter R, Samuel AD, Miller DM, Schnabel R, Calarco JA, Zhen M. Neuroendocrine modulation sustains the C. elegans forward motor state. eLife 2016; 5:19887. [PMID: 27855782 PMCID: PMC5120884 DOI: 10.7554/elife.19887] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/14/2016] [Indexed: 12/12/2022] Open
Abstract
Neuromodulators shape neural circuit dynamics. Combining electron microscopy, genetics, transcriptome profiling, calcium imaging, and optogenetics, we discovered a peptidergic neuron that modulates C. elegans motor circuit dynamics. The Six/SO-family homeobox transcription factor UNC-39 governs lineage-specific neurogenesis to give rise to a neuron RID. RID bears the anatomic hallmarks of a specialized endocrine neuron: it harbors near-exclusive dense core vesicles that cluster periodically along the axon, and expresses multiple neuropeptides, including the FMRF-amide-related FLP-14. RID activity increases during forward movement. Ablating RID reduces the sustainability of forward movement, a phenotype partially recapitulated by removing FLP-14. Optogenetic depolarization of RID prolongs forward movement, an effect reduced in the absence of FLP-14. Together, these results establish the role of a neuroendocrine cell RID in sustaining a specific behavioral state in C. elegans. DOI:http://dx.doi.org/10.7554/eLife.19887.001
Collapse
Affiliation(s)
- Maria A Lim
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Jyothsna Chitturi
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Valeriya Laskova
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.,Department of Physiology, University of Toronto, Toronto, Canada
| | - Jun Meng
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.,Department of Physiology, University of Toronto, Toronto, Canada
| | - Daniel Findeis
- Institut für Genetik, Technische Universität Braunschweig Carolo Wilhelmina, Braunschweig, Germany
| | - Anne Wiekenberg
- Institut für Genetik, Technische Universität Braunschweig Carolo Wilhelmina, Braunschweig, Germany
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Linjiao Luo
- Key Laboratory of Modern Acoustics, Ministry of Education, Department of Physics, Nanjing University, Nanjing, China
| | - Yan Li
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.,Department of Physiology, University of Toronto, Toronto, Canada
| | - Yangning Lu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.,Department of Physiology, University of Toronto, Toronto, Canada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Yixin Qu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Chi-Yip Ho
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Douglas Holmyard
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Ni Ji
- Center for Brain Science, Harvard University, Cambridge, United States.,Department of Physics, Harvard University, Cambridge, United States
| | - Rebecca McWhirter
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Aravinthan Dt Samuel
- Center for Brain Science, Harvard University, Cambridge, United States.,Department of Physics, Harvard University, Cambridge, United States
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Ralf Schnabel
- Institut für Genetik, Technische Universität Braunschweig Carolo Wilhelmina, Braunschweig, Germany
| | - John A Calarco
- FAS Center for Systems Biology, Harvard University, Cambridge, United States
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada.,Department of Physiology, University of Toronto, Toronto, Canada
| |
Collapse
|
30
|
Hums I, Riedl J, Mende F, Kato S, Kaplan HS, Latham R, Sonntag M, Traunmüller L, Zimmer M. Regulation of two motor patterns enables the gradual adjustment of locomotion strategy in Caenorhabditis elegans. eLife 2016; 5. [PMID: 27222228 PMCID: PMC4880447 DOI: 10.7554/elife.14116] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 04/19/2016] [Indexed: 11/18/2022] Open
Abstract
In animal locomotion a tradeoff exists between stereotypy and flexibility: fast long-distance travelling (LDT) requires coherent regular motions, while local sampling and area-restricted search (ARS) rely on flexible movements. We report here on a posture control system in C. elegans that coordinates these needs. Using quantitative posture analysis we explain worm locomotion as a composite of two modes: regular undulations versus flexible turning. Graded reciprocal regulation of both modes allows animals to flexibly adapt their locomotion strategy under sensory stimulation along a spectrum ranging from LDT to ARS. Using genetics and functional imaging of neural activity we characterize the counteracting interneurons AVK and DVA that utilize FLP-1 and NLP-12 neuropeptides to control both motor modes. Gradual regulation of behaviors via this system is required for spatial navigation during chemotaxis. This work shows how a nervous system controls simple elementary features of posture to generate complex movements for goal-directed locomotion strategies. DOI:http://dx.doi.org/10.7554/eLife.14116.001 Animals navigate through their environment using different strategies according to their current needs. For example, when the goal is to travel long distances, they move quickly and in an efficient way by employing regular, repetitive movements. However, when the aim is to explore the nearby area – to search for food, for example – animals move slowly and make more flexible movements. These different types of movement mostly use the same groups of muscles, and so animals must be able to alter how they control their muscles to yield these different strategies. These movement strategies have been observed in many animal species, from worms to grazing cows, and researchers have mostly classified them into distinct behavioral states that the animals switch between. To date, the patterns of movements that underlie these strategies have not been described in detail. The wavelike movement of the roundworm Caenorhabditis elegans has the advantage of being relatively easy to measure. By analyzing precise recordings of how the worms change posture as they move, Hums et al. now show that two main patterns of motion underlie worm movement. Regular whole-body waves (undulations) efficiently drive long-distance travel, while more complex turning motions allow the animals to flexibly change direction and so explore the local environment. Furthermore, the worms can fine-tune their movement strategy by gradually transitioning between the two patterns. This finding is opposed to the standard view, where animals switch between distinct behavioral states. Hums et al. then studied how neuronal regulation in the C. elegans nervous system enables the worms to transition between the different movement strategies. In these experiments, neurons were manipulated and their activity was recorded. The results suggest that two classes of so called interneurons enable the worms to fine-tune their movements. Each class of these interneurons produces a signaling molecule (or neuropeptide) that counteracts the activity of the other signal; together both neuropeptides regulate the patterns of movements. Further work is now needed to identify and investigate the downstream neurons that work together to represent the different patterns of movements in the roundworm. Future studies could also analyze whether other animals – such as swimming animals and limbed animals – use similar principles to change between distinct forms of movement and thus enact a range of behavioral strategies. DOI:http://dx.doi.org/10.7554/eLife.14116.002
Collapse
Affiliation(s)
- Ingrid Hums
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Julia Riedl
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Fanny Mende
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Saul Kato
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Harris S Kaplan
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Richard Latham
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Michael Sonntag
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Lisa Traunmüller
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| | - Manuel Zimmer
- Research Institute of Molecular Pathology, Vienna Biocenter VBC, Vienna, Austria
| |
Collapse
|
31
|
Roberts WM, Augustine SB, Lawton KJ, Lindsay TH, Thiele TR, Izquierdo EJ, Faumont S, Lindsay RA, Britton MC, Pokala N, Bargmann CI, Lockery SR. A stochastic neuronal model predicts random search behaviors at multiple spatial scales in C. elegans. eLife 2016; 5:12572. [PMID: 26824391 PMCID: PMC4798983 DOI: 10.7554/elife.12572] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/19/2016] [Indexed: 12/20/2022] Open
Abstract
Random search is a behavioral strategy used by organisms from bacteria to humans to locate food that is randomly distributed and undetectable at a distance. We investigated this behavior in the nematode Caenorhabditis elegans, an organism with a small, well-described nervous system. Here we formulate a mathematical model of random search abstracted from the C. elegans connectome and fit to a large-scale kinematic analysis of C. elegans behavior at submicron resolution. The model predicts behavioral effects of neuronal ablations and genetic perturbations, as well as unexpected aspects of wild type behavior. The predictive success of the model indicates that random search in C. elegans can be understood in terms of a neuronal flip-flop circuit involving reciprocal inhibition between two populations of stochastic neurons. Our findings establish a unified theoretical framework for understanding C. elegans locomotion and a testable neuronal model of random search that can be applied to other organisms. An animal’s ability to rapidly and efficiently locate new sources of food in its environment can mean the difference between life and death. As a result, animals have evolved foraging strategies that are adapted to the distribution and detectability of food sources. Organisms ranging from bacteria to humans use one such strategy, called random search, to locate food that cannot be detected at a distance and that is randomly distributed in their surroundings. The biological mechanisms that underpin random search are relatively well understood in single-cell organisms such as bacteria, but this information tells us little about the mechanisms that are used by animals, which use their nervous system to control their foraging behavior. Roberts et al. have now investigated the biological basis for random search behavior in a tiny roundworm called Caenorhabditis elegans. This worm forages for pockets of bacteria in decaying plant matter and has a simple and well-understood nervous system. Roberts et al. used information on how the cells in this worm’s nervous system connect together into so-called “neural circuits” to generate a mathematical model of random searching. The model revealed that the worm’s neural circuitry for random searching can be understood in terms of two groups of neuron-like components that switch randomly between “ON” and “OFF” states. While one group promotes forward movement, the other promotes backward movement, which is associated with a change in search direction. These two groups inhibit each other so that only one group usually is active at a given time. By adjusting this model to reproduce the behavioral records of real worms searching for food, Roberts et al. could predict the key neuronal connections involved. These predictions were then confirmed by taking electrical recordings from neurons. The model could also account for the unexpected behavioral effects that are seen when a neuron in one of these groups was destroyed or altered by a genetic mutation. These findings thus reveal a biological mechanism for random search behavior in worms that might operate in other animals as well. The findings might also provide future insight into the neural circuits involved in sleep and wakefulness in mammals, which is organized in a similar way.
Collapse
Affiliation(s)
- William M Roberts
- Institute of Neuroscience, University of Oregon, Eugene, United States
| | - Steven B Augustine
- School of Nursing, University of Pennsylvania, Philadelphia, United States
| | | | - Theodore H Lindsay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Tod R Thiele
- Department of Biological Sciences, University of Toronto, Toronto, Canada
| | | | - Serge Faumont
- Institute of Neuroscience, University of Oregon, Eugene, United States
| | - Rebecca A Lindsay
- Department of Ophthalmology, The Vision Center, Children's Hospital Los Angeles, Los Angeles, United States
| | | | - Navin Pokala
- Department of Life Sciences, New York Institute of Technology, Old Westbury, United States
| | - Cornelia I Bargmann
- Howard Hughes Medical Institute, Rockefeller University, New York, United States
| | - Shawn R Lockery
- Institute of Neuroscience, University of Oregon, Eugene, United States
| |
Collapse
|
32
|
Catecholaminergic System of Invertebrates: Comparative and Evolutionary Aspects in Comparison With the Octopaminergic System. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 322:363-94. [PMID: 26940523 DOI: 10.1016/bs.ircmb.2015.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this review we examined the catecholaminergic system of invertebrates, starting from protists and getting to chordates. Different techniques used by numerous researchers revealed, in most examined phyla, the presence of catecholamines dopamine, noradrenaline, and adrenaline or of the enzymes involved in their synthesis. The catecholamines are generally linked to the nervous system and they can act as neurotransmitters, neuromodulators, and hormones; moreover they play a very important role as regards the response to a large number of stress situations. Nevertheless, in some invertebrate phyla belonging to Protostoma, the monoamine octopamine is the main biogenic amine. The presence of catecholamines in some protists suggests a role as intracellular or interorganismal signaling molecules and an ancient origin of their synthetic pathways. The catecholamines appear also involved in the regulation of bioluminescence and in the control of larval development and metamorphosis in some marine invertebrate phyla.
Collapse
|
33
|
Bhattacharya R, Francis MM. In the proper context: Neuropeptide regulation of behavioral transitions during food searching. WORM 2015; 4:e1062971. [PMID: 26430569 PMCID: PMC4588156 DOI: 10.1080/21624054.2015.1062971] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 05/27/2015] [Accepted: 06/11/2015] [Indexed: 12/22/2022]
Abstract
Neuromodulation enables transient restructuring of anatomically fixed neural circuits, generating alternate outputs and distinct states that allow for flexible organismal responses to changing conditions. We recently identified a requirement for the neuropeptide-like protein NLP-12, a Caenorhabditis elegans homolog of mammalian Cholecystokinin (CCK), in the control of behavioral responses to altered food availability. We showed that deletion of nlp-12 impairs turning during local food searching while nlp-12 overexpression is sufficient to induce deep body bends and enhance turning. nlp-12 is solely expressed in the DVA interneuron that is located postsynaptic to the dopaminergic PDE neurons and presynaptic to premotor and motor neurons, well-positioned for modulating sensorimotor tasks. Interestingly, DVA was previously implicated in a NLP-12 mediated proprioceptive feedback loop during C. elegans locomotion. Here, we discuss the modulatory effects of NLP-12 with an emphasis on the potential for circuit level integration with olfactory information about food availability. In addition, we propose potential mechanisms by which DVA may integrate distinct forms of sensory information to regulate NLP-12 signaling and mediate context-dependent modulation of the motor circuit.
Collapse
Affiliation(s)
- Raja Bhattacharya
- Department of Neurobiology; University of Massachusetts Medical School ; Worcester, MA USA
| | - Michael M Francis
- Department of Neurobiology; University of Massachusetts Medical School ; Worcester, MA USA
| |
Collapse
|