Whole-body connectome of a segmented annelid larva

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Март 17, 2024

Abstract Nervous systems coordinate effectors across the body during movements. We know little about cellular-level structure of synaptic circuits for such body-wide control. Here we describe whole-body connectome a segmented larva marine annelid Platynereis dumerilii . reconstructed and annotated over 9,000 neuronal non-neuronal cells in serial electron microscopy dataset. Differentiated were classified into 202 92 cell types. analyse modularity, multisensory integration, left-right intersegmental connectivity motor ciliated cells, glands, pigment muscles. identify several segment-specific types, demonstrating heteromery larval trunk. At same time, segmentally repeated types head, trunk segments pygidium suggest homology all segmental regions. also report descending ascending pathways, peptidergic multi-modal mechanosensory girdle. Our work provides basis understanding coordination an entire animal.

Язык: Английский

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Ciliomotor circuitry underlying whole-body coordination of ciliary activity in the Platynereis larva

eLife, Год журнала: 2017, Номер 6

Опубликована: Май 15, 2017

Ciliated surfaces harbouring synchronously beating cilia can generate fluid flow or drive locomotion. In ciliary swimmers, beating, arrests, and changes in beat frequency are often coordinated across extended discontinuous surfaces. To understand how such coordination is achieved, we studied the ciliated larvae of Platynereis dumerilii, a marine annelid. have segmental multiciliated cells that regularly display spontaneous arrests. We used whole-body connectomics, activity imaging, transgenesis, neuron ablation to characterize ciliomotor circuitry. identified cholinergic, serotonergic, catecholaminergic neurons. The synchronous rhythmic activation cholinergic drives arrests all cilia. serotonergic active when beating. Serotonin inhibits rhythm, increases frequency. Based on their connectivity alternating activity, may rhythm. circuitry thus constitutes stop-and-go pacemaker system for

Язык: Английский

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Convergence of monosynaptic and polysynaptic sensory paths onto common motor outputs in a Drosophila feeding connectome

eLife, Год журнала: 2018, Номер 7

Опубликована: Дек. 11, 2018

We reconstructed, from a whole CNS EM volume, the synaptic map of input and output neurons that underlie food intake behavior Drosophila larvae. Input originate enteric, pharyngeal external sensory organs converge onto seven distinct compartments within CNS. Output consist feeding motor, serotonergic modulatory neuroendocrine neurons. Monosynaptic connections set cover targets in overlapping domains. Polysynaptic routes are superimposed on top monosynaptic connections, resulting divergent paths common outputs. A completely different is connected to mushroom body calyx. The interneurons directly target Our results illustrate circuit architecture which multisynaptic inputs traverse via series converging paths.

Язык: Английский

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Ciliary and rhabdomeric photoreceptor-cell circuits form a spectral depth gauge in marine zooplankton

eLife, Год журнала: 2018, Номер 7

Опубликована: Май 29, 2018

Ciliary and rhabdomeric photoreceptor cells represent two main lines of photoreceptor-cell evolution in animals. The cell types coexist some animals, however how these functionally integrate is unknown. We used connectomics to map synaptic paths between ciliary photoreceptors the planktonic larva annelid Platynereis found that are presynaptic circuit. behaviors mediated by also interact hierarchically. UV-sensitive mediate downward swimming non-directional UV light, a behavior absent ciliary-opsin knockout larvae. avoidance overrides positive phototaxis eyes such vertical direction determined ratio blue/UV light. Since this increases with depth, larvae may use it as depth gauge during migration. Our results revealed functional integration zooplankton larva.

Язык: Английский

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Whole-animal connectome and cell-type complement of the three-segmented Platynereis dumerilii larva

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2020, Номер unknown

Опубликована: Авг. 22, 2020

Abstract Nervous systems coordinate effectors across the body during movements. We know little about cellular-level structure of synaptic circuits for such body-wide control. Here we describe whole-body connectome and cell-type complement a three-segmented larva marine annelid Platynereis dumerilii . reconstructed annotated over 1,500 neurons 6,500 non-neuronal cells in serial electron microscopy dataset. The differentiated fall into 180 neuronal 90 cell types. analyse modular network architecture entire nervous system polysynaptic pathways from 428 sensory to four effector – ciliated cells, glands, pigment muscles. complete somatic musculature its innervation will be described companion paper. also investigated intersegmental differences complement, descending ascending pathways, mechanosensory peptidergic circuits. Our work provides basis understanding coordination annelids.

Язык: Английский

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What Is Health?

The MIT Press eBooks, Год журнала: 2020, Номер unknown

Опубликована: Фев. 25, 2020

An argument that health is optimal responsiveness and often best treated at the system level. Medical education centers on venerable “no-fault” concept of homeostasis, whereby local mechanisms impose constancy by correcting errors, brain serves mainly for emergencies. Yet, it turns out most parameters are not constant; moreover, despite importance mechanisms, definitely in charge. In this book, eminent neuroscientist Peter Sterling describes a broader concept: allostasis (coined Joseph Eyer 1980s), anticipates needs efficiently mobilizes supplies to prevent errors. Allostasis evolved early, explains, optimize energy efficiency, relying heavily circuits deliver brief reward each positive surprise. Modern life so reduces opportunities surprise we driven seek consumption: bigger burgers, more opioids, innumerable activities involve higher carbon emissions. The consequences include addiction, obesity, type 2 diabetes, climate change. concludes solutions must go beyond merely technical restore possibilities daily small rewards revivify capacities egalitarianism were hard-wired into our nature. explains offers what found any medical textbook: principled definitions disease: as capacity adaptive variation disease shrinkage capacity. argues since responsiveness, many significant conditions

Язык: Английский

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Elementary nervous systems

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 2021, Номер 376(1821), С. 20200347 - 20200347

Опубликована: Фев. 8, 2021

The evolutionary origin of the nervous system has been a matter long-standing debate. This is due to different perspectives taken. Earlier studies addressed origins at cellular level. They focused on selective advantage first neuron in its local context, and considered vertical sensory-motor reflex arcs system. Later emphasized value tissue Rather than acting locally, early neurons were seen as part an elementary nerve net that enabled horizontal coordination movements. Opinions have also differed nature effector cells. While most authors favoured contractile systems, others see key output incipient motile cilia, or secretion antimicrobial peptides. I will discuss these divergent views explore how they can be validated by molecular single-cell data. From this survey, possible consensus emerges: (i) manifestation likely was net, whereas specialized circuits evolved later; (ii) nets may for cilia-driven movements; (iii) all evolving facilitated new forms animal behaviour with increasing body size. article theme issue ‘Basal cognition: multicellularity, cognitive lens’.

Язык: Английский

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Synaptic connectome of theDrosophilacircadian clock

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Сен. 13, 2023

The circadian clock and its output pathways play a pivotal role in optimizing daily processes. To obtain novel insights into how diverse rhythmic physiology behaviors are orchestrated, we have generated the first comprehensive connectivity map of an animal using Drosophila FlyWire brain connectome. Intriguingly, identified additional dorsal neurons, thus showing that network contains ∼240 instead 150 neurons. We also revealed extensive contralateral synaptic within discovered indirect light input to Interestingly, observed sparse monosynaptic between neurons down-stream higher-order centers neurosecretory cells known regulate behavior physiology. Therefore, integrated single-cell transcriptomics receptor mapping decipher putative paracrine peptidergic signaling by Our analyses neuropeptides expressed suggest significantly enriches interconnectivity network.

Язык: Английский

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Whole-Body Single-Cell Sequencing Reveals Transcriptional Domains in the Annelid Larval Body

Molecular Biology and Evolution, Год журнала: 2018, Номер 35(5), С. 1047 - 1062

Опубликована: Янв. 22, 2018

Animal bodies comprise diverse arrays of cells. To characterize cellular identities across an entire body, we have compared the transcriptomes single cells randomly picked from dissociated whole larvae marine annelid Platynereis dumerilii. We identify five transcriptionally distinct groups differentiated cells, each expressing a unique set transcription factors and effector genes that implement phenotypes. Spatial mapping into expression atlas, wholemount in situ hybridization group-specific reveals spatially coherent transcriptional domains larval comprising, for example, apical sensory-neurosecretory versus neural/epidermal surface These represent new, basic subdivisions body based entirely on differential gene expression, are composed multiple, similar cell types. They do not clonal domains, as revealed by developmental lineage analysis. propose subdivide families related types arisen evolutionary diversification. Their possible conservation makes them promising tool evo-devo research.

Язык: Английский

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Corazonin signaling integrates energy homeostasis and lunar phase to regulate aspects of growth and sexual maturation in Platynereis

Proceedings of the National Academy of Sciences, Год журнала: 2019, Номер 117(2), С. 1097 - 1106

Опубликована: Дек. 16, 2019

The molecular mechanisms by which animals integrate external stimuli with internal energy balance to regulate major developmental and reproductive events still remain enigmatic. We investigated this aspect in the marine bristleworm, Platynereis dumerilii , a species where sexual maturation is tightly regulated both metabolic state lunar cycle. Our specific focus was on ligands receptors of gonadotropin-releasing hormone (GnRH) superfamily. Members superfamily are key triggering vertebrates but also processes homeostasis invertebrates. Here we show that 3 4 gnrh-like ( gnrhl ) preprohormone genes expressed distinct neuronal clusters brain. Moreover, ligand–receptor interaction analyses reveal single corazonin receptor (CrzR) be activated CRZ1/GnRHL1, CRZ2/GnRHL2, GnRHL3 (previously classified as AKH1), whereas 2 AKH-type (GnRHR1/AKHR1 GnRHR2/AKHR2) respond only ligand (GnRH2/GnRHL4). Crz1/gnrhl1 exhibits particularly strong up-regulation sexually mature animals, after feeding, phases. Homozygous crz1/gnrhl1 knockout exhibit significant delay maturation, reduced growth, attenuated regeneration. Through combination proteomics gene expression analysis, identify enzymes involved carbohydrate metabolism transcriptional targets CRZ1/GnRHL1 signaling. data suggest coordinates glycoprotein turnover growth integrating demands worm’s monthly

Язык: Английский

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