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1.
Elife ; 82019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31526477

RESUMO

The nematodes C. elegans and P. pacificus populate diverse habitats and display distinct patterns of behavior. To understand how their nervous systems have diverged, we undertook a detailed examination of the neuroanatomy of the chemosensory system of P. pacificus. Using independent features such as cell body position, axon projections and lipophilic dye uptake, we have assigned homologies between the amphid neurons, their first-layer interneurons, and several internal receptor neurons of P. pacificus and C. elegans. We found that neuronal number and soma position are highly conserved. However, the morphological elaborations of several amphid cilia are different between them, most notably in the absence of 'winged' cilia morphology in P. pacificus. We established a synaptic wiring diagram of amphid sensory neurons and amphid interneurons in P. pacificus and found striking patterns of conservation and divergence in connectivity relative to C. elegans, but very little changes in relative neighborhood of neuronal processes. These findings demonstrate the existence of several constraints in patterning the nervous system and suggest that major substrates for evolutionary novelty lie in the alterations of dendritic structures and synaptic connectivity.


Assuntos
Interneurônios/citologia , Rede Nervosa/anatomia & histologia , Sistema Nervoso/anatomia & histologia , Rabditídios/anatomia & histologia , Células Receptoras Sensoriais/citologia , Animais
2.
Brain Behav Evol ; 93(2-3): 92-107, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31416070

RESUMO

The common marmoset, a New World (platyrrhine) monkey, is currently being fast-tracked as a non-human primate model species, especially for genetic modification but also as a general-purpose model for research on the brain and behavior bearing on the human condition. Compared to the currently dominant primate model, the catarrhine macaque monkey, marmosets are notable for certain evolutionary specializations, including their propensity for twin births, their very small size (a result of phyletic dwarfism), and features related to their small size (rapid development and relatively short lifespan), which result in these animals yielding experimental results more rapidly and at lower cost. Macaques, however, have their own advantages. Importantly, macaques are more closely related to humans (which are also catarrhine primates) than are marmosets, sharing approximately 20 million more years of common descent, and are demonstrably more similar to humans in a variety of genomic, molecular, and neurobiological characteristics. Furthermore, the very specializations of marmosets that make them attractive as experimental subjects, such as their rapid development and short lifespan, are ways in which marmosets differ from humans and in which macaques more closely resemble humans. These facts warrant careful consideration of the trade-offs between convenience and cost, on the one hand, and biological realism, on the other, in choosing between non-human primate models of human biology. Notwithstanding the advantages marmosets offer as models, prudence requires continued commitment to research on macaques and other primate species.


Assuntos
Evolução Biológica , Callithrix/anatomia & histologia , Macaca/anatomia & histologia , Modelos Animais , Sistema Nervoso/anatomia & histologia , Animais , Callithrix/fisiologia , Macaca/fisiologia
3.
Adv Clin Exp Med ; 28(8): 1125-1135, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31414731

RESUMO

In recent years, many attempts have been made to connect electrical circuits with the human nervous system. The objective of type of research was diverse - from the desire to understand the physiology of the nervous system, through attempting to substitute nervous tissue defects with synthetic systems, to creating an interface that allows computers to be controlled directly with one's thought. Regardless of the original purpose, the creation of any form of such a combination would entail a series of subsequent discoveries, allowing for a real revolution in both theoretical and clinical neuroscience. Computers based on neurons, neurochips or mind prostheses are just some examples of technologies that could soon become part of everyday life. Despite numerous attempts, there is still no interface that meets all the expectations of the scholars. However, many scientific groups seem to be on the right track and their achievements raise extraordinary expectations. This paper evaluates historical theories and contemporary ideas about such interfaces to smoothly describe the major medical and scientific utility of the subject. Thus it presents the main issues surrounding the concept of integrating the human nervous system with electronic circuits.


Assuntos
Membros Artificiais , Eletrônica , Sistema Nervoso , Humanos , Sistema Nervoso/anatomia & histologia , Fenômenos Fisiológicos do Sistema Nervoso , Neurônios
4.
Med Hypotheses ; 131: 109297, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31443774

RESUMO

Multiple sclerosis (MS) is an immune-mediated disease which can cause different symptoms due to the involvement of different regions of the central nervous system (CNS). Although this disease is characterized by the demyelination process, the most important feature of the disease is its degenerative nature. This nature is clinically manifested as progressive symptoms, especially in patients' walking, which can even lead to complete debilitation. Therefore, finding a treatment to prevent the degenerative processes is one of the most important goals in MS studies. To better understand the process and the effect of drugs, scientists use animal models which mostly consisting of mouse, rat, and monkey. In evolutionary terms, octopuses belong to the invertebrates which have many substantial differences with vertebrates. One of these differences is related to the nervous system of these organisms, which is divided into central and peripheral parts. The difference lies in the fact that the main volume of this system expands in the limbs of these organisms instead of their brain. This offers a kind of freedom of action and processing strength in the octopus limbs. Also, the brain of these organisms follows a non-somatotopic model. Although the complex actions of this organism are stimulated by the brain, in contrast to the human brain, this activity is not related to a specific region of the brain; rather the entire brain area of the octopus is activated during a process. Indeed, the brain mapping or the topological perception of a particular action, such as moving the limbs, reflects itself in how that activity is distributed in the octopus brain neurons. Accordingly, various actions are known with varying degrees of activity of neurons in the brain of octopus. Another important feature of octopuses is their ability to regenerate defective tissues including the central and peripheral nervous system. These characteristics raise the question of what features can an octopus show when it is used as an organism to create experimental autoimmune encephalomyelitis (EAE). Can the immune system damage of the octopus brain cause a regeneration process? Will the autonomy of the organs reduce the severity of the symptoms? This article seeks to provide evidence to prove that use of octopuses as laboratory samples for generation of EAE may open up new approaches for researchers to better approach MS.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Esclerose Múltipla/fisiopatologia , Fenômenos Fisiológicos do Sistema Nervoso , Sistema Nervoso/anatomia & histologia , Octopodiformes/anatomia & histologia , Animais , Axônios/fisiologia , Extremidades/lesões , Extremidades/inervação , Extremidades/fisiologia , Hemócitos/fisiologia , Humanos , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Esclerose Múltipla/imunologia , Fenômenos Fisiológicos do Sistema Nervoso/imunologia , Plasticidade Neuronal , Octopodiformes/imunologia , Octopodiformes/fisiologia , Regeneração/fisiologia , Especificidade da Espécie , Traumatismos do Sistema Nervoso/fisiopatologia
5.
BMC Evol Biol ; 19(1): 173, 2019 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462293

RESUMO

BACKGROUND: The annelid anterior central nervous system is often described to consist of a dorsal prostomial brain, consisting of several commissures and connected to the ventral ganglionic nerve cord via circumesophageal connectives. In the light of current molecular phylogenies, our assumptions on the primary design of the nervous system in Annelida has to be reconsidered. For that purpose we provide a detailed investigation of the adult nervous system of Magelonidae - a putatively basally branching annelid family - and studied early stages of the development of the latter. RESULTS: Our comparative investigation using an integrative morphological approach shows that the nervous system of Magelonidae is located inside the epidermis. The brain is composed of an anterior compact neuropil and posteriorly encircles the prostomial coelomic cavities. From the brain two lateral medullary cords branch off which fuse caudally. Prominent brain structures such as nuchal organs, ganglia or mushroom bodies are absent and the entire nervous system is medullary. Our investigations also contradict previous investigations and present an updated view on established assumptions and descriptions. CONCLUSION: The comprehensive dataset presented herein enables a detailed investigation of the magelonid anterior central nervous system for the first time. The data reveal that early in annelid evolution complexity of brains and anterior sensory structures rises. Polymorphic neurons in clusters and distinct brain parts, as well as lateral organs - all of which are not present in outgroup taxa and in the putative magelonid sister group Oweniidae - already evolved in Magelonidae. Commissures inside the brain, ganglia and nuchal organs, however, most likely evolved in the stem lineage of Amphinomidae + Sipuncula and Pleistoannelida (Errantia+ Sedentaria). The investigation demonstrates the necessity to continuously question established descriptions and interpretations of earlier publications and the need for transparent datasets. Our results also hint towards a stronger inclusion of larval morphology and developmental investigations in order to understand adult morphological features, not only in Annelida.


Assuntos
Evolução Biológica , Poliquetos/genética , Animais , Encéfalo/anatomia & histologia , Encéfalo/citologia , Larva/crescimento & desenvolvimento , Sistema Nervoso/anatomia & histologia , Sistema Nervoso/citologia , Filogenia , Poliquetos/anatomia & histologia , Poliquetos/citologia , Poliquetos/crescimento & desenvolvimento
6.
Nature ; 571(7763): 63-71, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31270481

RESUMO

Knowledge of connectivity in the nervous system is essential to understanding its function. Here we describe connectomes for both adult sexes of the nematode Caenorhabditis elegans, an important model organism for neuroscience research. We present quantitative connectivity matrices that encompass all connections from sensory input to end-organ output across the entire animal, information that is necessary to model behaviour. Serial electron microscopy reconstructions that are based on the analysis of both new and previously published electron micrographs update previous results and include data on the male head. The nervous system differs between sexes at multiple levels. Several sex-shared neurons that function in circuits for sexual behaviour are sexually dimorphic in structure and connectivity. Inputs from sex-specific circuitry to central circuitry reveal points at which sexual and non-sexual pathways converge. In sex-shared central pathways, a substantial number of connections differ in strength between the sexes. Quantitative connectomes that include all connections serve as the basis for understanding how complex, adaptive behavior is generated.


Assuntos
Caenorhabditis elegans/metabolismo , Conectoma , Sistema Nervoso/anatomia & histologia , Sistema Nervoso/metabolismo , Caracteres Sexuais , Animais , Comportamento Animal , Caenorhabditis elegans/citologia , Feminino , Cabeça/anatomia & histologia , Cabeça/inervação , Organismos Hermafroditas , Masculino , Microscopia Eletrônica , Atividade Motora , Movimento , Sistema Nervoso/citologia , Vias Neurais
7.
Eur. j. anat ; 23(supl.1): 5-14, jun. 2019. ilus
Artigo em Inglês | IBECS | ID: ibc-183844

RESUMO

In the second half of the 19th century Spain was rather isolated from the rest of Europe, although there was remarkable scientific activity. In the midst of this scenario, the figure of Cajal emerged on the scene. During a visit to the laboratory of Luis Simarro in Madrid in 1887, Cajal became acquainted with a paper published by Golgi in 1873 dealing with his famous method. Cajal immediately recognized the value of this method and applied it with much success to the study of the nervous tissue. In the triennium 1887-1889 Cajal's discoveries were so sensational that he decided to attend the meeting of the Anatomische Gesellschaft (Germany Anatomical Society) in Berlin in 1889 in order to present them abroad. The trip proved a great success, and he was able to establish close relations with the president of the society, Alexander von Kölliker, who, in turn, mediated contacts with further renowned scientists such as Retzius, His, Waldeyer, van Gehuchten, etc. Prior to his trip to Berlin, he had already contacted Golgi, but the fact that Cajal's neuronal theory conflicted with Golgi's reticular theory not only prevented a normal relationship between them, but was also -especially on Golgi's part- the source of bitter rivalry between them. Von Kölliker immediately recognized and admired Cajal's stature as a scientist and generously helped him to publicize his ideas throughout the scientific world, and to attain the recognition he deserved. Von Kölliker's relationship with Golgi was of a different nature, and could be described as sincere friendship. Von Kölliker, in fact, proposed both Golgi and Cajal as candidates for the Nobel Prize in 1906, which was subsequently awarded to them jointly. Thanks to Von Kölliker, Cajal's great mentor, the neuronal theory entered the scientific world through the main door and continues to occupy a prevailing position


No disponible


Assuntos
Humanos , História do Século XIX , Sistema Nervoso/anatomia & histologia , Anatomia/história , Neurônios , Filosofia/história , Teoria de Sistemas , Teoria Psicológica , Complexo de Golgi , Neurofisiologia/história
8.
Eur. j. anat ; 23(supl.1): 57-66, jun. 2019. ilus
Artigo em Inglês | IBECS | ID: ibc-183849

RESUMO

Santiago Ramón y Cajal created histological images using a variety of artistic techniques and methods. In order to contextualise his practice, I have selected a set of drawings and prints of cartilage cells that were used in Cajal’s reference handbooks. I then introduce a lithograph representing an inflamed cartilage included in Cajal’s first publication. This technique enabled the publishing of graphic information in colour. By reviewing images included in the material that Cajal consulted during his pre-graduate years, I show that he participated in the transnational production of drawing and made use of the printing techniques available to present his research. By analysing a set of original drawings included in Cajal´s notebook, Diario de Observaciones, and his first published lithographs of cartilage cells and neurons, I reveal the graphic specificities of his transition from handmade drawings to print representations. Cajal´s drawing and lithographing relate directly to artistic interests developed in his youth (López Piñero, 1985), and these skills facilitated the technical transit between notebook and published images, enabling him to formalise his knowledge by including histological results in printed material. A determining factor in Cajal’s graphic production relating to the nervous system was his expertise in using chemical silver nitrate, resulting from his interest in photography. Finally, his colour selection is discussed, in order to demonstrate that, even when Cajal drew black lines, he was using black as a specific colour, one he observed through the microscope after staining histological samples


No disponible


Assuntos
História do Século XIX , Conhecimento , Neurociências/história , Patologia/educação , Patologia/história , Sistema Nervoso/anatomia & histologia , Neuroglia , Neurociências/educação , Gravuras e Gravação/classificação , Gravuras e Gravação/história
9.
J Helminthol ; 94: e52, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31084661

RESUMO

Data on the interposition of the immunoreactive nerve cords in Cercaria parvicaudata Stunkard & Shaw, 1931 (Trematoda: Renicolidae) and its chaetotaxy were obtained. The nervous system of C. parvicaudata was described using immunostaining of 5-hydroxytryptamine and FMRFamide immunoreactive nerve elements. The morphology and distribution of sensory receptors were analysed using scanning electron microscopy and the silver nitrate impregnation technique. Our integrated approach to the study of the nervous system revealed a clear colocalization of surface papillae with nerve cords and commissures in C. parvicaudata. The structure of the nervous system in C. parvicaudata differs partly from the classical model that defines the entire nomenclature of chaetotaxy.


Assuntos
Cercárias/anatomia & histologia , Sistema Nervoso/anatomia & histologia , Células Receptoras Sensoriais/ultraestrutura , Animais , Microscopia Eletrônica de Varredura , Sistema Nervoso/ultraestrutura , Nitrato de Prata , Manejo de Espécimes , Coloração e Rotulagem
10.
BMC Evol Biol ; 19(1): 86, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30961520

RESUMO

BACKGROUND: The Scalidophora (Kinorhyncha, Loricifera and Priapulida) have an important phylogenetic position as early branching ecdysozoans, yet the architecture of their nervous organ systems is notably underinvestigated. Without such information, and in the absence of a stable phylogenetic context, we are inhibited from producing adequate hypotheses about the evolution and diversification of ecdysozoan nervous systems. Here, we utilize confocal laser scanning microscopy to characterize serotonergic, tubulinergic and FMRFamidergic immunoreactivity patterns in a comparative neuroanatomical study with three species of Echinoderes, the most speciose, abundant and diverse genus within Kinorhyncha. RESULTS: Neuroanatomy in Echinoderes as revealed by acetylated α-tubulin immunoreactivity includes a circumpharyngeal brain and ten neurite bundles in the head region that converge into five longitudinal nerves within the trunk. The ventral nerve cord is ganglionated, emerging from the brain with two connectives that converge in trunk segments 2-3, and diverge again within segment 8. The longitudinal nerves and ventral nerve cord are connected by two transverse neurites in segments 2-9. Differences among species correlate with the number, position and innervation of cuticular structures along the body. Patterns of serotoninergic and FMRFamidergic immunoreactivity correlate with the position of the brain neuropil and the ventral nerve cord. Distinct serotonergic and FMRFamidergic somata are associated with the brain neuropil and specific trunk segments along the ventral nerve cord. CONCLUSIONS: Neural architecture is highly conserved across all three species, suggesting that our results reveal a pattern that is common to more than 40% of the species within Kinorhyncha. The nervous system of Echinoderes is segmented along most of the trunk; however, posterior trunk segments exhibit modifications that are likely associated with sensorial, motor or reproductive functions. Although all kinorhynchs show some evidence of an externally segmented trunk, it is unclear whether external segmentation matches internal segmentation of nervous and muscular organ systems across Kinorhyncha, as we observed in Echinoderes. The neuroanatomical data provided in this study not only expand the limited knowledge on kinorhynch nervous systems but also establish a comparative morphological framework within Scalidophora that will support broader inferences about the evolution of neural architecture among the deepest branching lineages of the Ecdysozoa.


Assuntos
Eucariotos/fisiologia , Microscopia Confocal/métodos , Sistema Nervoso/anatomia & histologia , Neuroanatomia , Acetilação , Animais , FMRFamida/metabolismo , Filogenia , Serotonina/metabolismo , Tubulina (Proteína)/metabolismo
11.
Parasitol Res ; 118(4): 1193-1203, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30725179

RESUMO

The development of metacercariae of Diplostomum pseudospathaceum Niewiadomska, 1984 is accompanied by profound morphological transformations often characterized as metamorphosis, which makes these metacercariae an interesting case for studying the morphogenesis of the digenean nervous system. Although the nervous system of D. pseudospathaceum is one of the most extensively studied among digeneans, there are still gaps in our knowledge regarding the distribution patterns of some neuroactive substances, most notably neuropeptides. The present study addresses these gaps by studying pre-infective metacercariae of D. pseudospathaceum using immunochemical staining and confocal microscopy to characterize the distribution patterns of serotonin (5-HT) and two major groups of flatworm neuropeptides, FMRFamide-related (FaRPs) and substance P-related (SP) peptides. The general morphology of the nervous system was examined with antibodies to alpha-tubulin. The nervous system of the metacercariae was shown to conform to the most common morphology of the nervous system in the hermaphroditic generation, with three pairs of posterior nerve cords and four pairs of anterior nerves. The patterns of FaRP- and 5-HT immunoreactivity (IR) were similar to those revealed in earlier studies by cholinesterase activity, which is in accordance with the known role of these neurotransmitters in controlling muscle activity in flatworms. The SP-IR nervous system was significantly different and consisted of mostly bipolar cells presumably acting as mechanoreceptors. The architecture of the nervous system in D. pseudospathaceum metacercariae is discussed in comparison to that in cercariae of D. pseudospathaceum and metacercariae of related digenean species.


Assuntos
FMRFamida/metabolismo , Metacercárias/anatomia & histologia , Sistema Nervoso/anatomia & histologia , Substância P/metabolismo , Trematódeos/anatomia & histologia , Animais , Metacercárias/fisiologia , Metamorfose Biológica , Microscopia Confocal , Fenômenos Fisiológicos do Sistema Nervoso , Serotonina/metabolismo , Coloração e Rotulagem , Trematódeos/fisiologia , Tubulina (Proteína)/imunologia
12.
Rev Neurol (Paris) ; 175(3): 119-125, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30293880

RESUMO

Alexandria's famous medical school was established about 300 BC. It was the seat of learning for many Greco-Roman physicians. The physiologist Erasistratus, the anatomist Herophilus - named the Father of Anatomy were outstanding pioneers. Their work and discoveries of the nervous system, its structure and function, are described. In the 2nd century AD they were succeeded by Rufus of Ephesus - the medical link between Hippocrates and Galen, - and Aretaeus a leading anatomist and physician in this period.


Assuntos
Mundo Grego/história , Fenômenos Fisiológicos do Sistema Nervoso , Sistema Nervoso/anatomia & histologia , Sistema Nervoso/patologia , Faculdades de Medicina/história , Anatomia/história , História Antiga , Humanos , Patologia Clínica/história , Médicos/história , Fisiologia/história
13.
Prog Brain Res ; 243: 109-138, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30514521

RESUMO

This chapter examines Sir Charles Bell's visual inquiries into the nervous system. Taking as our cue four watercolors currently housed in the UCL Art Collections, we explore Bell's approach to representing the brain and the nervous system by placing these works in the broader context of his visual approach to anatomy and his equally committed practices in the visual arts. We show that Bell's visual displays aimed at the production of complex arguments that brought together theoretical and systematic knowledge, experimentation on the nervous system, and aesthetics.


Assuntos
Anatomia/história , Ilustração Médica/história , Sistema Nervoso/anatomia & histologia , História do Século XVIII , História do Século XIX , Humanos , Masculino , Pinturas/história
14.
Int. j. morphol ; 36(4): 1262-1267, Dec. 2018. graf
Artigo em Inglês | LILACS | ID: biblio-975693

RESUMO

The anatomy and histology of the nervous system in the mussel Choromytilus chorus were studied. Juvenile specimens of C. chorus and adult broodstock were collected in Laraquete Cove, Chile (37°09'S; 37°11'O). The juveniles were used for histological analysis and the adults for a macroscopic description of anatomical. The histological description was carried out by Gallego´s trichrome technique. The macroscopic analysis showed that nervous system network includes three pairs of ganglia of orange color and little size (20-40 mm) (cerebral, pedal and visceral) located in the anterior, middle and posterior zone of the specimen, respectively. The histological analysis showed many type de cells inside the ganglia (neurosecretory, granulated and glial cells). The ganglia network could be involving in regulating several physiological processes in the mussels through of their neurosecretions.


Se estudió la anatomía e histología del sistema nervioso en el coro Choromytilus del mejillón. Se recolectaron especímenes juveniles de C. coros y reproductores adultos en Laraquete Cove, Chile (37 ° 09'S, 37 ° 11'O). Los especímenes juveniles se utilizaron para el análisis histológico y los adultos para una descripción macroscópica de anatómica. La descripción histológica se realizó mediante la técnica de tricrómico de Gallego. El análisis macroscópico mostró que la red del sistema nervioso incluye tres pares de ganglios de color naranjo y poco tamaño (20-40 mm) (cerebral, pedal y visceral) localizados en la zona anterior, media y posterior de la muestra, respectivamente. El análisis histológico mostró muchos tipos de células dentro de los ganglios (células neurosecretoras, granuladas y gliales). La red de ganglios podría estar involucrada en la regulación de varios procesos fisiológicos en los mejillones a través de sus neurosecreciones.


Assuntos
Animais , Bivalves/anatomia & histologia , Sistema Nervoso/anatomia & histologia , Sistemas Neurossecretores/anatomia & histologia , Chile
15.
Handb Clin Neurol ; 159: 3-26, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30482322

RESUMO

The review demonstrates that control of posture and locomotion is provided by systems across the caudal-to-rostral extent of the neuraxis. A common feature of the neuroanatomic organization of the postural and locomotor control systems is the presence of key nodes for convergent input of multisensory feedback in conjunction with efferent copies of the motor command. These nodes include the vestibular and reticular nuclei and interneurons in the intermediate zone of the spinal cord (Rexed's laminae VI-VIII). This organization provides both spatial and temporal coordination of the various goals of the system and ensures that the large repertoire of voluntary movements is appropriately coupled to either anticipatory or reactive postural adjustments that ensure stability and provide the framework to support the intended action. Redundancies in the system allow adaptation and compensation when sensory modalities are impaired. These alterations in behavior are learned through reward- and error-based learning processes implemented through basal ganglia and cerebellar pathways respectively. However, neurodegenerative processes or lesions of these systems can greatly compromise the capacity to sufficiently adapt and sometimes leads to maladaptive changes that impair movement control. When these impairments occur, the risk of falls can be significantly increased and interventions are required to reduce morbidity.


Assuntos
Acidentes por Quedas , Marcha/fisiologia , Sistema Nervoso/anatomia & histologia , Equilíbrio Postural/fisiologia , Humanos , Modelos Anatômicos
16.
Artigo em Inglês | MEDLINE | ID: mdl-30201842

RESUMO

The OpenWorm project has the ambitious goal of producing a highly detailed in silico model of the nematode Caenorhabditis elegans A crucial part of this work will be a model of the nervous system encompassing all known cell types and connections. The appropriate level of biophysical detail required in the neuronal model to reproduce observed high-level behaviours in the worm has yet to be determined. For this reason, we have developed a framework, c302, that allows different instances of neuronal networks to be generated incorporating varying levels of anatomical and physiological detail, which can be investigated and refined independently or linked to other tools developed in the OpenWorm modelling toolchain.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling C. elegans at cellular resolution'.


Assuntos
Caenorhabditis elegans/fisiologia , Conectoma/métodos , Modelos Neurológicos , Fenômenos Fisiológicos do Sistema Nervoso , Animais , Simulação por Computador , Sistema Nervoso/anatomia & histologia
17.
Wiley Interdiscip Rev Syst Biol Med ; 10(6): e1425, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29862670

RESUMO

The nonlinear systems models of computational anatomy that have emerged over the past several decades are a synthesis of three significant areas of computational science and biological modeling. First is the algebraic model of biological shape as a Riemannian orbit, a set of objects under diffeomorphic action. Second is the embedding of anatomical shapes into the soft condensed matter physics continuum via the extension of the Euler equations to geodesic, smooth flows with inverses, encoding divergence for the compressibility of atrophy and expansion of growth. Third, is making human shape and form a metrizable space via geodesic connections of coordinate systems. These three themes place our formalism into the modern data science world of personalized medicine supporting inference of high-dimensional anatomical phenotypes for studying neurodegeneration and neurodevelopment. The dynamical systems model of growth and atrophy that emerges is one which is organized in terms of forces, accelerations, velocities, and displacements, with the associated Hamiltonian momentum and the diffeomorphic flow acting as the state, and the smooth vector field the control. The forces that enter the model derive from external measurements through which the dynamical system must flow, and the internal potential energies of structures making up the soft condensed matter. We examine numerous examples on growth and atrophy. This article is categorized under: Analytical and Computational Methods > Computational Methods Laboratory Methods and Technologies > Imaging Models of Systems Properties and Processes > Organ, Tissue, and Physiological Models.


Assuntos
Modelos Biológicos , Sistema Nervoso/anatomia & histologia , Algoritmos , Encéfalo/fisiologia , Humanos
18.
BMC Evol Biol ; 18(1): 92, 2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29898669

RESUMO

BACKGROUND: Cyclostome bryozoans are an ancient group of marine colonial suspension-feeders comprising approximately 700 extant species. Previous morphological studies are mainly restricted to skeletal characters whereas data on soft tissues obtained by state-of-the-art methods are still lacking. In order to contribute to issues related to cyclostome ground pattern reconstruction, we analyzed the morphology of the neuromuscular system Cinctipora elegans by means of immunocytochemical staining, confocal laser scanning microscopy, histological sections and microCT imaging. RESULTS: Polypides of C. elegans are located in elongated tubular skeletal cystids. Distally, the orifice leads into a prominent vestibulum which is lined by an epithelium that joins an almost complete perimetrical attachment organ, both containing radially arranged neurite bundles and muscles. Centrally, the prominent atrial sphincter separates the vestibulum from the atrium. The latter is enclosed by the tentacle sheath which contains few longitudinal muscle fibers and two principal neurite bundles. These emerge from the cerebral ganglion, which is located at the lophophoral base. Lateral ganglia are located next to the cerebral ganglion from which the visceral neurite bundles emerge that extend proximally towards the foregut. There are four tentacle neurite bundles that emerge from the ganglia and the circum-oral nerve ring, which encompasses the pharynx. The tentacles possess two striated longitudinal muscles. Short buccal dilatators are situated at the lophophoral base and short muscular sets are present at the abfrontal and frontal side of the tentacle base. The pharynx is myoepithelial and triradiate in cross-section. Oocytes are found inside the pharyngeal myoepithelium. The digestive tract contains dense circular musculature and few longitudinal muscles. The membranous sac contains regular, thin, circular and diagonal muscles and neurites in its epithelial lining. CONCLUSIONS: The general structure of the neuro-muscular system is more reminiscent of the condition found in Gymnolaemata rather than Phylactolaemata, which supports a close relationship between Cyclostomata and Gymnolaemata. Several characters of C. elegans such as the lateral ganglia or loss of the cardia are probably apomorphic for this species. For the first time, oocytes that surprisingly develop in the pharyngeal wall are reported for this species.


Assuntos
Briozoários/anatomia & histologia , Briozoários/fisiologia , Músculos/anatomia & histologia , Sistema Nervoso/anatomia & histologia , Estruturas Animais/anatomia & histologia , Estruturas Animais/inervação , Animais , Trato Gastrointestinal/anatomia & histologia , Microscopia Confocal , Oócitos/citologia , Reprodução/fisiologia , Serotonina/metabolismo , Microtomografia por Raio-X
19.
Annu Rev Neurosci ; 41: 349-369, 2018 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-29709211

RESUMO

The recently determined connectome of the Caenorhabditis elegans adult male, together with the known connectome of the hermaphrodite, opens up the possibility for a comprehensive description of sexual dimorphism in this species and the identification and study of the neural circuits underlying sexual behaviors. The C. elegans nervous system consists of 294 neurons shared by both sexes plus neurons unique to each sex, 8 in the hermaphrodite and 91 in the male. The sex-specific neurons are well integrated within the remainder of the nervous system; in the male, 16% of the input to the shared component comes from male-specific neurons. Although sex-specific neurons are involved primarily, but not exclusively, in controlling sex-unique behavior-egg-laying in the hermaphrodite and copulation in the male-these neurons act together with shared neurons to make navigational choices that optimize reproductive success. Sex differences in general behaviors are underlain by considerable dimorphism within the shared component of the nervous system itself, including dimorphism in synaptic connectivity.


Assuntos
Caenorhabditis elegans/fisiologia , Sistema Nervoso , Vias Neurais/fisiologia , Caracteres Sexuais , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Sistema Nervoso/anatomia & histologia , Sistema Nervoso/citologia
20.
Annu Rev Immunol ; 36: 783-812, 2018 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-29677475

RESUMO

The nervous system regulates immunity and inflammation. The molecular detection of pathogen fragments, cytokines, and other immune molecules by sensory neurons generates immunoregulatory responses through efferent autonomic neuron signaling. The functional organization of this neural control is based on principles of reflex regulation. Reflexes involving the vagus nerve and other nerves have been therapeutically explored in models of inflammatory and autoimmune conditions, and recently in clinical settings. The brain integrates neuro-immune communication, and brain function is altered in diseases characterized by peripheral immune dysregulation and inflammation. Here we review the anatomical and molecular basis of the neural interface with immunity, focusing on peripheral neural control of immune functions and the role of the brain in the model of the immunological homunculus. Clinical advances stemming from this knowledge within the framework of bioelectronic medicine are also briefly outlined.


Assuntos
Neuroimunomodulação , Animais , Biomarcadores , Suscetibilidade a Doenças , Humanos , Imunidade , Sistema Nervoso/anatomia & histologia , Sistema Nervoso/imunologia , Sistema Nervoso/metabolismo , Fenômenos Fisiológicos do Sistema Nervoso , Neuroimunomodulação/genética , Neuroimunomodulação/imunologia , Transdução de Sinais , Pesquisa Médica Translacional
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