Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.153
Filtrar
1.
Proc Biol Sci ; 287(1931): 20201198, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32693729

RESUMO

The origin of bilateral symmetry, a major transition in animal evolution, coincided with the evolution of organized nervous systems that show regionalization along major body axes. Studies of Xenacoelomorpha, the likely outgroup lineage to all other animals with bilateral symmetry, can inform the evolutionary history of animal nervous systems. Here, we characterized the neural anatomy of the acoel Hofstenia miamia. Our analysis of transcriptomic data uncovered orthologues of enzymes for all major neurotransmitter synthesis pathways. Expression patterns of these enzymes revealed the presence of a nerve net and an anterior condensation of neural cells. The anterior condensation was layered, containing several cell types with distinct molecular identities organized in spatially distinct territories. Using these anterior cell types and structures as landmarks, we obtained a detailed timeline for regeneration of the H. miamia nervous system, showing that the anterior condensation is restored by eight days after amputation. Our work detailing neural anatomy in H. miamia will enable mechanistic studies of neural cell type diversity and regeneration and provide insight into the evolution of these processes.


Assuntos
Sistema Nervoso/anatomia & histologia , Platelmintos/fisiologia , Animais , Regeneração
2.
Arthropod Struct Dev ; 56: 100933, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32259775

RESUMO

Stick insects have elaborate mechanosensory organs in their subgenual organ complex in the proximal tibia, particularly the distal organ with scolopidial sensilla in linear arrangement. For early postembryonic developmental stages of Sipyloidea sipylus (Phasmatodea: Necrosciinae), the neuroanatomy of the scolopidial organs in the subgenual organ complex and the campaniform sensilla is documented by retrograde axonal tracing, and compared to the adult neuroanatomy. Already after hatching of the first larval instars are the sensory structures of subgenual organ and distal organ as well as tibial campaniform sensilla differentiated. In the distal organ, the full set of sensilla is shown in all larval stages examined. This finding indicates that the sensory organs differentiate during embryogenesis, and are already functional by the time of hatching. The constancy of distal organ sensilla over postembryonic stages allows investigation of the representative number of sensilla in adult animals as well as in larval instars. Some anatomical changes occur by postembryogenic length increase of the distal organ, and grouping of the anterior subgenual sensilla. The embryonic development of scolopidial sensilla is similar for auditory sensilla in hemimetabolous Orthoptera (locusts, bushcrickets, crickets) where tympanal membranes develop during postembryogenic stages, conferring a successive gain of sensitivity with larval moults.


Assuntos
Neópteros/crescimento & desenvolvimento , Animais , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Microscopia , Neópteros/anatomia & histologia , Sistema Nervoso/anatomia & histologia , Sistema Nervoso/crescimento & desenvolvimento , Sensilas/anatomia & histologia , Sensilas/crescimento & desenvolvimento
3.
PLoS One ; 15(3): e0221006, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32187190

RESUMO

Homeodomain-interacting protein kinases (Hipks) have been previously associated with cell proliferation and cancer, however, their effects in the nervous system are less well understood. We have used Drosophila melanogaster to evaluate the effects of altered Hipk expression on the nervous system and muscle. Using genetic manipulation of Hipk expression we demonstrate that knockdown and over-expression of Hipk produces early adult lethality, possibly due to the effects on the nervous system and muscle involvement. We find that optimal levels of Hipk are critical for the function of dopaminergic neurons and glial cells in the nervous system, as well as muscle. Furthermore, manipulation of Hipk affects the structure of the larval neuromuscular junction (NMJ) by promoting its growth. Hipk regulates the phosphorylation of the synapse-associated cytoskeletal protein Hu-li tai shao (Hts; adducin in mammals) and modulates the expression of two important protein kinases, Calcium-calmodulin protein kinase II (CaMKII) and Partitioning-defective 1 (PAR-1), all of which may alter neuromuscular structure/function and influence lethality. Hipk also modifies the levels of an important nuclear protein, TBPH, the fly orthologue of TAR DNA-binding protein 43 (TDP-43), which may have relevance for understanding motor neuron diseases.


Assuntos
Proteínas de Drosophila/isolamento & purificação , Drosophila melanogaster/enzimologia , Drosophila melanogaster/fisiologia , Músculos/anatomia & histologia , Músculos/metabolismo , Sistema Nervoso/anatomia & histologia , Sistema Nervoso/metabolismo , Proteínas Quinases/isolamento & purificação , Animais , Padronização Corporal , Núcleo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/anatomia & histologia , Olho/embriologia , Larva/metabolismo , Masculino , Músculos/citologia , Sistema Nervoso/citologia , Junção Neuromuscular/metabolismo , Tamanho do Órgão , Fosforilação , Sinapses/metabolismo
4.
Anat Histol Embryol ; 49(1): 17-24, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30793353

RESUMO

Stereology is a method for examining two-dimensional objects as three-dimensional objects. The aim of this study was to offer volume values for thoracic segments in ducks by means of stereological methods. This study examined the data obtained from stereological analysis of the total volume and grey and white matter volume values of the thoracic segment, a part of the adult duck spinal cord with a weight of 3-4 kg. In the study, study samples consisted of 10 adult ducks (Anas) used without gender discrimination. To perfuse all of the animals, 10% formaldehyde was utilised. The perfused animals were kept in 10% formaldehyde for one week. The spinal cord was uncovered following the removal of arcus vertebrae parts of thoracic vertebrae in the thoracic part of dissected ducks. Tissue samples of thoracic segments were taken; 5-µm-thick cross sections from these tissue samples were taken via microtome. Attention was paid to obtaining samples at the ratio of 1/250 by taking 12 cross sections from each segment. The cross sections were subjected to haematoxylin-eosin staining. Photographs of all cross sections were taken using a microscope. The volume values of all tissue and grey and white matter structures in each thoracic segment of the spinal cord were calculated. The total volume, grey and white matter volume densities in thoracic segments of ducks, as well as the data obtained as a result of proportioning volume values of one another are represented in the conclusion section of this study.


Assuntos
Substância Cinzenta/anatomia & histologia , Medula Espinal/anatomia & histologia , Vértebras Torácicas/anatomia & histologia , Substância Branca/anatomia & histologia , Animais , Patos , Processamento de Imagem Assistida por Computador , Microscopia , Sistema Nervoso/anatomia & histologia
5.
Bull Exp Biol Med ; 168(2): 295-299, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31782006

RESUMO

Adrenergic innervation in the tissue of the thyroid gland, blood vessels of the thyroid gland, cervical lymphatic vessel, and lymph nodes in rats with hypothyroidism was studied by using a specific histochemical fluorescent-microscopic method of visualization of catecholamines. The presence of adrenergic innervation in the blood and lymph vessels and nodes was demonstrated. In hypothyroidism, diffusion of norepinephrine from nerve fibers and varicose thickenings was observed in the wall of the upper and lower thyroid arteries and adjacent cervical lymphatic vessels and nodes.


Assuntos
Fibras Adrenérgicas/fisiologia , Vasos Sanguíneos/inervação , Hipotireoidismo/patologia , Linfonodos/inervação , Vasos Linfáticos/inervação , Glândula Tireoide/inervação , Neurônios Adrenérgicos/fisiologia , Animais , Catecolaminas/química , Catecolaminas/metabolismo , Corantes Fluorescentes/química , Masculino , Sistema Nervoso/anatomia & histologia , Ratos
6.
J Morphol ; 280(11): 1628-1650, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31487090

RESUMO

Sipuncula is a clade of unsegmented marine worms that are currently placed among the basal radiation of conspicuously segmented Annelida. Their new location provides a unique opportunity to reinvestigate the evolution and development of segmented body plans. Neural segmentation is clearly evident during ganglionic ventral nerve cord (VNC) formation across Sedentaria and Errantia, which includes the majority of annelids. However, recent studies show that some annelid taxa outside of Sedentaria and Errantia have a medullary cord, without ganglia, as adults. Importantly, neural development in these taxa is understudied and interpretation can vary widely. For example, reports in sipunculans range from no evidence of segmentation to vestigial segmentation as inferred from a few pairs of serially repeated neuronal cell bodies along the VNC. We investigated patterns of pan-neuronal, neuronal subtype, and axonal markers using immunohistochemistry and whole mount in situ hybridization (WMISH) during neural development in an indirect-developing sipunculan, Themiste lageniformis. Confocal imaging revealed two clusters of 5HT+ neurons, two pairs of FMRF+ neurons, and Tubulin+ peripheral neurites that appear to be serially positioned along the VNC, similar to other sipunculans, to other annelids, and to spiralian taxa outside of Annelida. WMISH of a synaptotagmin1 ortholog in T. lageniformis (Tl-syt1) showed expression throughout the centralized nervous system (CNS), including the VNC where it appears to correlate with mature 5HT+ and FMRF+ neurons. An ortholog of elav1 (Tl-elav1) showed expression in differentiated neurons of the CNS with continuous expression in the VNC, supporting evidence of a medullary cord, and refuting evidence of ontogenetic segmentation during formation of the nervous system. Thus, we conclude that sipunculans do not exhibit any signs of morphological segmentation during development.


Assuntos
Larva/crescimento & desenvolvimento , Sistema Nervoso/crescimento & desenvolvimento , Neurogênese , Poliquetos/crescimento & desenvolvimento , Animais , Regulação da Expressão Gênica no Desenvolvimento , Larva/anatomia & histologia , Microscopia Confocal , Sistema Nervoso/anatomia & histologia , Neurônios , Poliquetos/anatomia & histologia , Poliquetos/genética
7.
Sci Adv ; 5(9): eaax5858, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31535028

RESUMO

Annelid worms are a disparate, primitively segmented clade of bilaterians that first appear during the early Cambrian Period. Reconstructing their early evolution is complicated by the extreme morphological diversity in early diverging lineages, rapid diversification, and sparse fossil record. Canadia spinosa, a Burgess Shale fossil polychaete, is redescribed as having palps with feeding grooves, a dorsal median antenna and biramous parapodia associated with the head and flanking a ventral mouth. Carbonaceously preserved features are identified as a terminal brain, circumoral connectives, a midventral ganglionated nerve cord and prominent parapodial nerves. Phylogenetic analysis recovers neuroanatomically simple extant taxa as the sister group of other annelids, but the phylogenetic position of Canadia suggests that the annelid ancestor was reasonably complex neuroanatomically and that reduction of the nervous system occurred several times independently in the subsequent 500 million years of annelid evolution.


Assuntos
Evolução Biológica , Fósseis/anatomia & histologia , Sistema Nervoso/anatomia & histologia , Poliquetos/anatomia & histologia , Poliquetos/classificação , Animais , Comportamento Alimentar , Sistema Nervoso/crescimento & desenvolvimento , Filogenia
8.
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
9.
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
10.
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
11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
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
18.
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
19.
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
20.
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
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA