Search

Recent years have witnessed a steady increase in reports of fossilized nervous tissues among Cambrian total-group euarthropods, which allow reconstructing the early evolutionary history of these animals. Here, we describe the central nervous system of the stem-group chelicerate Mollisonia symmetrica from the mid-Cambrian Burgess Shale. The fossilized neurological anatomy of M. symmetrica includes optic nerves connected to a pair of lateral eyes, a putative condensed cephalic synganglion, and a metameric ventral nerve cord. Each trunk tergite is associated with a condensed ganglion bearing lateral segmental nerves, and linked by longitudinal connectives. The nervous system is preserved as reflective carbonaceous films underneath the phosphatized digestive tract. Our results suggest that M. symmetrica illustrates the ancestral organization of stem-group Chelicerata before the evolution of the derived neuroanatomical characters observed in Cambrian megacheirans and extant representatives. Our findings reveal a conflict between the phylogenetic signals provided by neuroanatomical and appendicular data, which we interpret as evidence of mosaic evolution in the chelicerate stem-lineage., (© 2022. The Author(s).)

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.

Studies on the bryozoan adult nervous system employing immunocytochemical techniques and confocal laser scanning microscopy are scarce. To gain a better view into the structure and evolution of the nervous system of the Phylactolaemata, the earliest extant branch and sister taxon to the remaining Bryozoa, this work aims to characterize the nervous system of Hyalinella punctata with immunocytochemical techniques and confocal laser scanning microscopy. The cerebral ganglion is located between the anus and the pharynx and contains a lumen. Two ganglionic horns and a circum-oral nerve ring emanate from the cerebral ganglion. The pharynx is innervated by a diffuse neural plexus with two prominent neurite bundles. The caecum is innervated by longitudinal neurite bundles and a peripheral plexus. The intestine is characterized by longitudinal and circular neurite bundles, mostly near the anus. Novel putative sensory cells were found in the foregut and intestine. The tentacle sheath is innervated by a diffuse neural plexus, which emanates from several neurite bundles from the cerebral ganglion, but also parts of the pharyngeal plexus. There are six tentacle neurite bundles of intertentacular origin. The retractor muscles are innervated by two thin neurite bundles. Several characters are described herein for the first time in Phylactolaemata: Longitudinal neurite bundles and a peripheral plexus of the caecum, putative sensory structures of the gut, retractor muscle innervation, specific duplicature band neurite bundles. The tentacle innervation differs from previous descriptions of phylactolaemates regarding the origin of the three abfrontal neurite bundles. In general, most organ systems are innervated by a diffuse plexus in phylactolaemates as opposed to gymnolaemates. In contrast to the Gymnolaemata, representatives of Phylactolaemata show a higher number of tentacle nerves. Although the plesiomorphic condition for zooidal features among bryozoans remains unclear, having a diffuse nerve plexus may represent an ancestral feature for freshwater bryozoans., (© 2017 Wiley Periodicals, Inc.)

Today's neuroanatomical terminology has its origins in the Romans' way of life, in their civil and military house architecture, as well as in the fields of engineering and technology. Despite the fact that they did not know how the nervous system worked and what the role of each neuroanatomic structure was, over time, especially in Renaissance and early modern times, the anatomists sought descriptive names for the nervous structures they have identified by way of similarity with some ancient items. This study aims to briefly review the influence of Roman architecture, engineering, and technology on neuroanatomic nomenclature, the precursor of modern neuroanatomical terminology.

Wishing to contribute to an easier remembrance of the name, shape, location and function of some neuroanatomical structures, this paper aims to identify the origin of eight Latin terms (pulvinar, capsula, infundibulum, operculum, flocculus, forceps, falx, habenula). Therefore, we analyzed the etymology of these Latin neuroanatomical terms in brief, and searched the possible correlations between the shape of different household objects used in Roman Antiquity and the shape of neuroanatomical structures bearing those names. We also perused the literature to identify the first anatomist who made such an analogy when searching to give a name to the anatomical structure he had discovered at dissection, as well as the time context of his discovery. We found knowledge of few neuroanatomical structures tracing their origin to Antiquity, but most of the nervous structures we have studied were discovered in the 19th century, when the German school of anatomy played a distinctive part. However, the multitude of Latin words designating neuroanatomical structures by analogy is an undeniable proof of neuroanatomists' amazing imagination., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

One in six Americans is currently affected by neurologic disease. As the United States population ages, the number of neurologic complaints is expected to increase. Thus, there is a pressing need for more neurologists as well as more neurology training in other specialties. Often interest in neurology begins during medical school, so improving education in medical neural courses is a critical step toward producing more neurologists and better neurology training in other specialists. To this end, a novel applied neuroanatomy elective was designed at the University of Texas Health Science Center at San Antonio (UTHSCSA) to complement the traditional first-year medical neuroscience course and promote engagement and deep learning of the material with a focus on neurosensory pathways. The elective covered four neurosensory modalities (proprioception/balance, vision, auditory, and taste/olfaction) over four sessions, each with a short classroom component and a much longer activity component. At each session, students reviewed the neurosensory pathways through structured presentations and then applied them to preplanned interactive activities, many of which allowed students to utilize their artistic talents. Students were required to complete subjective pre-course and post-course surveys and reflections. The survey results and positive student comments suggest that the elective was a valuable tool when used in parallel with the traditional medical neuroscience course in promoting engagement and reinforcement of the neurosensory material., (© 2014 American Association of Anatomists.)

The treatise "De structura nervorum" by Jiří Procháska was published in 1779 and is remarkable not only for its anatomical and histological findings but also for its historical introduction, which contains a detailed bibliographical review of the contemporary knowledge of the structure of the nervous tissue. Unfortunately, the treatise has never been translated from the Latin language, but it deserves further analysis as a historical document about the level of neuroscience research conducted by a famous Czech scholar. The present article includes a historical overview of the contemporary knowledge of the structure of the nervous tissue up to the late eighteenth century from the perspective of today, a translation of selected chapters from Prochaska's treatise (a historical introduction about the medieval knowledge of the structure of the nervous tissue and an interpretation of his neurohistological observations), and an analysis of Jiří Prochaska's results in light of current knowledge.

The invention of the microscope at the beginning of the seventeenth century was a pivotal event for subsequent studies of the microscopic structure of nerve tissue. The present article, using translations of the original texts, presents a recollection of the discoveries made during the second half of the seventeenth century up to the beginning of the nineteenth century by prominent scholars as well as those nearly forgotten today. The findings in the field of neuroanatomy are collected together into a coherent form and in chronological order, showing the progress of the discoveries from a historical perspective. The early scientists discovered, and then repeatedly confirmed, that nerve tissue was remarkably similar over a wide range of animal forms. While they offered little detail, and much of what was described was flawed because of various technical restraints of the time, what they did report was very similar from animal to animal. Their studies, however, in parallel with the improvement of microscopic techniques as well as the processing and fixation of animal tissues, helped to create fertile ground for a number of important neurohistological discoveries in the first half of the nineteenth century.

Efforts were already made in antiquity to understand the structure and function of the brain and nervous tissue, but an important impulse for the development of neuroanatomy as a field was the invention of the microscope at the beginning of the 17th century. A brief overview of the history of research of the brain and nerve structure from Marcello Malpighi to Christian Berres shows by what small steps and with what difficulties the investigation of the composition of the nervous tissue advanced. The study of historical sources reveals that despite constantly improving microscopic techniques, many prominent researchers obtained inaccurate data and, on the basis of such data, often reached erroneous conclusions. However, these observations and their interpretation and, in addition, the clashing opinions of scholars of that period greatly influenced the work of later researchers in the field of the microscopic structure and function of the nervous tissue.

The treatise "De structura nervorum" by Jirí Procháska was published in 1779 after his appointment as a professor in Prague. This work is remarkable not only for its anatomical and histological findings, but also for its historical introduction, which contains a very detailed bibliographical review of previous knowledge about the structure of the nervous tissue. The treatise "De structura nervorum" has never been translated from the Latin language, but as a historical document about the level of neuroscience research conducted by a famous Czech researcher, it deserves further analysis. The present article includes a historical overview of knowledge about the structure of nervous tissue up to the late 18th century from the perspective of today, a translation of the historical introduction about the medieval knowledge of the structure of the nervous tissue and documenting the way in which Jirí Procháska processed his bibliography, a translation and interpretation of his neurohistological observations and an analysis of the results in the light of current knowledge.

Motivation: Advancing our understanding of how nervous systems work will require the ability to store and annotate 3D anatomical datasets, recording morphology, partonomy and connectivity at multiple levels of granularity from subcellular to gross anatomy. It will also require the ability to integrate this data with other data-types including functional, genetic and electrophysiological data. The web ontology language OWL2 provides the means to solve many of these problems. Using it, one can rigorously define and relate classes of anatomical structure using multiple criteria. The resulting classes can be used to annotate datasets recording, for example, gene expression or electrophysiology. Reasoning software can be used to automate classification and error checking and to construct and answer sophisticated combinatorial queries. But for such queries to give consistent and biologically meaningful results, it is important that both classes and the terms (relations) used to relate them are carefully defined., Results: We formally define a set of relations for recording the spatial and connectivity relationships of neuron classes and brain regions in a broad range of species, from vertebrates to arthropods. We illustrate the utility of our approach via its application in the ontology that drives the Virtual Fly Brain web resource., Availability and Implementation: The relations we define are available from http://purl.obolibrary.org/obo/ro.owl. They are used in the Drosophila anatomy ontology (http://purl.obolibrary.org/obo/fbbt/2011-09-06/), which drives the web resource http://www.virtualflybrain.org

The chapter provides an itinerary of knowledge on nervous system anatomy as one of the pillars of clinical neurology. The journey starts from the Renaissance explosion on the approach to the human body, its functions and its diseases, dealing with the seminal contributions of Leonardo da Vinci and Vesalius. The itinerary proceeds through the contributions of the 17th century, especially by Thomas Willis and the pioneering investigations of Marcello Malpighi and Antony van Leeuwenhoek, and onto the 18th century. The itinerary thus leads to the progress from gross anatomy to the microscopic investigation of the nervous system in the 19th century: the reticular theories, the revolution of the neural doctrine and their protagonists (Camillo Golgi and Santiago Ramón y Cajal), which initiated the modern era of the neurosciences. The chapter also includes sections on the contributions of developmental neuroanatomy to neurology, on the history of tract tracing, and on the cytoarchitecture of the cerebral cortex. The never-ending story of the anatomical foundations of clinical neurology continues to evolve at the dawn of the 21st century, including knowledge that guides deep brain stimulation, and novel approaches to the anatomy of the living brain based on rapidly developing neuroimaging technology.

Functional Neuroanatomy, an interactive electronic neuroanatomical atlas, was designed for first year medical students. Medical students have much to learn in a limited time; therefore a major goal in the atlas design was that it facilitate rapid, accurate information retrieval. To assess this feature, we designed a testing scenario in which students who had never taken a neuroanatomy course were asked to complete two equivalent tests, one using the electronic atlas and one using a comparable hard copy atlas, in a limited period of time. The tests were too long to be completed in the time allotted, so test scores were measures of how quickly correct information could be retrieved from each source. Statistical analysis of the data showed that the tests were of equal difficulty and that accurate information retrieval was significantly faster using the electronic atlas when compared with the hard copy atlas (P < 0.0001). Post-test focus groups (n = 4) allowed us to infer that the following design features contributed to rapid information access: the number of structures in the database was limited to those that are relevant to a practicing physician; all of the program modules were presented in both text and image form on the index screen, which doubled as a site map; pages were layered electronically such that information was hidden until requested, structures available on each page were listed alphabetically and could be accessed by clicking on their name; and an illustrated glossary was provided and equipped with a search engine.

Girolamo Fabrici d'Acquapendente (ca.1533-1619), in his olograph will donated to the Signoria of Venice a rich collection of anatomical paintings, which are today preserved in the Marciana Library. The third volume of these tabulae pictae, entitled De Anatomia Capitis Cerebri Nervorum, deals with the nervous system and contains the only known illustrations by Fabrici regarding neuroanatomy. Despite the realisation of this splendid collection of 21 coloured paintings, neither a systematic description nor an iconographic record regarding nervous structures were found to be published by Fabrici. For this reason, a thorough study of these plates is pivotal to a better understanding of the contribution made by d'Acquapendente to the knowledge of the nervous system. Besides their aesthetic quality, Fabrici's tabulae pictae appear as a unique document of exceptional scientific value, thanks to the unprecedented realism given to the anatomical structures by the innovative use of colours. These pictures represent the highest point reached by the 16th-century Paduan Medical School well demonstrating its aim for a sound naturalistic approach.

Samuel Thomas Soemmerring (1755-1830) was an encyclopaedic anatomist and one of the most experienced and renowned neuro-anatomists in the late eighteenth century. His description and illustration of the brainstem with its still accepted classification of cranial nerves (1778), the discovery of the acervulus in the epiphysis (1785), his demonstration of the crossing of the optic nerve fibres (1788), and of the macula lutea in the retina of the eye he had discovered in 1791, won him great recognition. Probably, unaware of Francesco Gennari's (1750-1797) and Félix Vicq d'Azyr's (1748-1794) observation, Soemmerring in the final years of the eighteenth century saw the broad white line running through the calcarine cortex of the occipital lobe. Soemmerring's comprehensive textbooks on the nervous system Vom Hirn and Rückenmark, 1788/1792, and Hirn- und Nervenlehre as part of his anatomical handbook Vom Baue des menschlichen Körpers, 1791/2nd edn, 1800, comprise all the knowledge in the field of neuro-anatomy at his time. Although the structure-function relationships mentioned are generally hypothetical, Soemmerring was convinced that mental faculties are executed in certain brain regions. In his treatise Uber das Organ der Seele, 1796, he localized the functions of the soul within the cerebrospinal fluid, which should come into close contact with the demonstrated and presumed nerve endings in the walls of the ventricular cavities. This last attempt of a synthesis of anatomy and metaphysics provoked passionate discussions and was criticised for epistemological reasons. Nevertheless, Soemmerring had moved the brain into the centre of the science of man what led to far-reaching consequences in the complexity of the discourse about man.

This report describes magnetic resonance imaging (MRI) methods we have developed at 9.4 T for observing internal organs and the nervous system of an invertebrate organism, the crayfish, Cherax destructor. We have compared results acquired using two different pulse sequences, and have tested manganese (Mn(2+)) as an agent to enhance contrast of neural tissues in this organism. These techniques serve as a foundation for further development of functional MRI and neural tract-tracing methods in non-vertebrate systems.

Auguste Forel was born in 1848 in the French part of Switzerland. He developed a lifelong passion for myrmecology in his childhood, but chose medicine and neuropsychiatry to earn his living. He first undertook a comparative study of the thalamus under Theodor Meynert in Vienna and then, from 1872 to 1879, he worked as Assistant Physician to Bernhard von Gudden in Munich. This led in 1877 to his seminal work on the organization of the tegmental region in which he provides the first description of the zona incerta and the so-called H (Haubenfeld) fields that still bear his name. In 1879, Forel was appointed Professor of Psychiatry in Munich and Director of the Burghölzli cantonal asylum. He became interested in the therapeutic value of hypnotism, while continuing his work on brain anatomy and ants. His neuroanatomical studies with Gudden's method led him to formulate the neuron theory in 1887, four years before Wilhelm von Waldeyer, who received most of the credit for it. Forel then definitively turned his back on neuroscience. After his retirement from the Burghölzli asylum in 1898. and despite a stroke in 1911 that left him hemiplegic, Forel started to write extensively on various social issues, such as alcohol abstinence and sexual problems. Before his death in 1931 at the age of 83, Forel published a remarkable book on the social world of the ants in which he made insightful observations on the neural control of sensory and instinctive behavior common to both humans and insects.

Neuroanatomical tract-tracing methods are powerful tools for the study of brain circuits. The use of axonal tracers has become very popular during the past few years. Tract-tracing allows us to study the way in which two or more brain areas are connected and can be used to obtain detailed data on the processing of information within a particular area. The recent development of protocols combining several tracers has resulted in an important breakthrough. Although technically very demanding, these multitracer procedures have become state of the art protocols in several laboratories, rendering a broad range of possibilities for their application in Neurobiology.

The fissure separating the motor from the sensory cortex and the substantia gelatinosa capping the posterior horn of the spinal cord are still known by the name of the Italian anatomist Rolando, Luigi Rolando was born in Turin, Italy, in 1773 and died in 1831. His life was not easy, the first of his problems being the death of his father when Rolando was still very young. Three people were to be influential in his life and career: Father Maffei, his maternal uncle who raised him; Dr. Cigna, the anatomy professor who discovered his talent; and Dr. Anformi, a general practitioner who introduced him to the practice of medicine and to the best circles of the city. Forced to leave Turin by the Napoleonic invasion of the country, Rolando first stopped in Florence, where he learned about anatomical dissection, drawing, and engraving and studied the appearance of nervous tissue under the microscope. Later he went to Sardinia where, although cut off from European cultural circles, he developed his major theories. Rolando pioneered the idea that brain functions could be differentiated and located in specific areas and discovered the fixed pattern of cerebral convolutions, highlighting motor and sensory gyri. He demonstrated the complexity of the central gray matter of the spinal cord, describing the "substantia gelatinosa," and he deduced that nervous structures are connected in a network of nervous fibers linked by electrical impulses. Rolando had to struggle for recognition, however, as the priority of his discoveries was challenged by the almost contemporaneous work of Gall and Spurzheim on cerebral localization and of Flourens on cerebellar function. Nevertheless, his efforts contributed greatly to the clarification of brain function. His observations on nervous anatomy have been especially accurate, as shown by the nomenclature "fissure of Rolando."

The science of stereology has undergone a revolution over the past decade with the introduction of design-based (assumption- or model-free) methods which are highly efficient and generally unbiased. No other morphometric approach currently offers these twin benefits. Stereology is ideal for extrapolating 3-D structural quantities (real volumes, surface areas, lengths and numbers) from simple counts made on 2-D slice images. The images may take various forms (e.g. physical or optical sections, MRI slices, CT scans) but they must be sampled so as to be random in orientation and/or position if valid estimates are to be made. All the recent developments in stereology are applicable to problems in neuromorphometry. This review provides an account of major developments and the state of the art, emphasizes the importance of properly randomized sampling and identifies some applications to neural structure at different levels of organization. These include the counting and sizing of synapses, neurites, cells and whole brains.

The usefulness of a number of new stereological principles for unbiased estimation of particle number and sizes and sampling of particles is illustrated together with a novel principle for unbiased estimation of anisotropic surfaces. The examples include descriptions of estimators of neurone and synapse number and sizes, synapse gradients, neurone point patterns in three-dimensional space, capillary surface area, and perikarya volumes. A major advantage of the methods is the possibility to carry out the estimation procedures in specified, well-characterized regions or layers of the brain. Some general statistical and stereological problems are briefly discussed.

Ganglia processed through the osmium-ethyl gallate procedure (OEG)19 retain more structural integrity than those processed through various silver impregnation methods. However, the OEG method continues to be neglected by most neuroanatomists. Both types of procedures have been used to trace large neuronal tracts, but during silver impregnation the neuropils lose many of their identifying characteristics. We demonstrate here the advantages of the OEG procedure by comparing it with two silver techniques, Rowell's and Holmes's. The OEG method yields consistent and reliable results and is easier to carry out than silver protocols. Most importantly, the better preservation of the neuropils has led to the discovery and study of regional specializations that were previously undetected from silver preparations.

A software package is described to reconstruct three-dimensional pictures in true perspective from a series of parallel sections using a low-cost computer system (Apple II plus). Data sampling via a graphic tablet and graphical output on the monitor screen or a digital plotter are assigned to different programs under control of a menu program. The number of data representing the object under study is unlimited. Originally written in BASIC, the programs were translated to machine language. As an application of the package, reconstructions of an identified large interneuron of the locust brain are presented.

Retrograde axonal transport and fluorescent retrograde labelling of neurons were investigated in a crustacean motor system. A fluorescent tracer (Granular blue) was injected into an antennal muscle of rock lobster in order to identify the motor neurons innervating it. After an appropriate post-injection survival time, the fluorescent tracer was found to have labelled motor neurons in the central ganglion. This result indicates that after uptake by the axon terminals, the fluorescent tracer was retrogradely transported through axons of motor neurons to the parent cell bodies.

In years prior, articles concerned with neuroanatomy have stressed just that, the anatomy. It is for this reason that this article was written. The primary intent addresses the clinical aspects of neuroanatomy, and as such, has stressed so-called "anatomic function." An overview of neuroanatomy as well as neural function and deficit is provided. The article is intended for both the student and practitioner in the hopes of taking the labor out of its study and replacing it with a logical approach to the neuroanatomy and its clinical applications.