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Journal of Morphology May 1995This study deals with some macroscopical, microscopical, and ultrastructural aspects of the spinal cord central canal of the German shepherd dog. The caudal end of the...
This study deals with some macroscopical, microscopical, and ultrastructural aspects of the spinal cord central canal of the German shepherd dog. The caudal end of the spinal cord is constituted by the conus medullaris, which may extend to the first sacral vertebra, the terminal ventricle, and the filum terminale. The latter structure is considered as internum (second to third sacral vertebrae) or externum (fifth caudal vertebra), according to its relation to the dura mater. Occasionally, there is a second anchorage which is close to the level of the sixth caudal vertebra. The central canal is surrounded by a ciliated ependymal epithelium, which differs depending upon the levels. The most caudal part of the filum terminale bears a columnar ciliated ependymal epithelium surrounded by two layers of glia and pia mater, which separate the central canal from the subarachnoid space. Microfil injections show a communication between the cavity and the subarachnoid space, as the plastic is able to pass through the ependymal epithelium. At the level of the terminal ventricle there are real separations of the ependymal epithelium, which seem to connect the lumen of the spinal canal with the subarachnoid space. These structures probably constitute one of the drainage pathways of the cerebrospinal fluid. The diameter of the central canal is related to the age of the animal. However, even in very old animals the spinal cord central canal reaches the tip of the filum terminale and remains patent until death. At the ultrastructural level the ependymal cells present villi, located on cytoplasmic projections, cilia, dense mitochondria, and oval nuclei.
Topics: Animals; Dogs; Male; Spinal Cord
PubMed: 7745605
DOI: 10.1002/jmor.1052240209 -
Spinal Cord Aug 2008
Topics: Animals; Cell- and Tissue-Based Therapy; Humans; Spinal Cord; Spinal Cord Injuries
PubMed: 18685603
DOI: 10.1038/sc.2008.91 -
Seminars in Musculoskeletal Radiology Oct 2023This article describes the vascular anatomy of the spine and spinal cord, highlighting key structures and anatomical variations relevant to musculoskeletal radiologists....
This article describes the vascular anatomy of the spine and spinal cord, highlighting key structures and anatomical variations relevant to musculoskeletal radiologists. It covers the arterial and venous drainage systems, along with examples of vascular conditions affecting the spine. Understanding the vascular anatomy of the spine and spinal cord is crucial for accurate interpretation of imaging studies and safe spinal interventional procedures. Imaging techniques for evaluating vascular pathology of the spine are discussed and compared. Understanding vascular anatomy and the most common vascular disorders will lead to an accurate diagnosis and suggest the appropriate type of study needed for further characterization and/or patient management.
Topics: Humans; Spinal Cord; Spine
PubMed: 37816366
DOI: 10.1055/s-0043-1772171 -
Nursing Mirror Sep 1982
Topics: Humans; Reflex; Spinal Cord; Spinal Nerves
PubMed: 6923334
DOI: No ID Found -
Annals of the New York Academy of... Nov 1998Previous studies have demonstrated that (1) NMDA receptor activation occurs during locomotor network operation in lower and higher vertebrates and (2) NMDA induces... (Review)
Review
Previous studies have demonstrated that (1) NMDA receptor activation occurs during locomotor network operation in lower and higher vertebrates and (2) NMDA induces active membrane properties that can be expressed as intrinsic voltage fluctuations in cells located in the spinal cord of lower vertebrates, as well as in neurons located in supraspinal regions of the mammalian nervous system. This paper reviews recent data showing that NMDA can induce similar inherent membrane potential behavior in synaptically isolated motoneurons and interneurons in the mammalian (in vitro neonatal rat) spinal cord. These TTX-resistant voltage fluctuations include rhythmic oscillations and plateau potentials, as well as low-frequency long-lasting voltage shifts (LLVSs). 5-HT facilitates the transformation of LLVSs into oscillatory events, and 5-HT receptor antagonists have the reverse effect. In the absence of TTX, locomotor-related rhythmic drive potentials in spinal cord neurons can display nonlinear voltage behavior compatible with NMDA receptor activation, although other voltage-activated conductances are not excluded. Suppression of the nonlinear voltage response associated with NMDA receptor activation, via removal of Mg2+, disrupts locomotor patterns of network activity. The potential role of NMDA receptor activation in the operation of mammalian locomotor networks is discussed in the context of these recent observations.
Topics: Animals; Locomotion; Mammals; Motor Neurons; Periodicity; Receptors, N-Methyl-D-Aspartate; Spinal Cord
PubMed: 9928312
DOI: 10.1111/j.1749-6632.1998.tb09049.x -
Scientific Reports Oct 2020This study aims to evaluate how parameters derived from diffusion tensor imaging reflect axonal disruption and demyelination in specific white matter tracts within the...
This study aims to evaluate how parameters derived from diffusion tensor imaging reflect axonal disruption and demyelination in specific white matter tracts within the spinal cord of squirrel monkeys following traumatic injuries, and their relationships to function and behavior. After a unilateral section of the dorsal white matter tract of the cervical spinal cord, we found that both lesioned dorsal and intact lateral tracts on the lesion side exhibited prominent disruptions in fiber orientation, integrity and myelination. The degrees of pathological changes were significantly more severe in segments below the lesion than above. The lateral tract on the opposite (non-injured) side was minimally affected by the injury. Over time, RD, FA, and AD values of the dorsal and lateral tracts on the injured side closely tracked measurements of the behavioral recovery. This unilateral section of the dorsal spinal tract provides a realistic model in which axonal disruption and demyelination occur together in the cord. Our data show that specific tract and segmental FA and RD values are sensitive to the effects of injury and reflect specific behavioral changes, indicating their potential as relevant indicators of recovery or for assessing treatment outcomes. These observations have translational value for guiding future studies of human subjects with spinal cord injuries.
Topics: Animals; Behavior, Animal; Cervical Vertebrae; Demyelinating Diseases; Diffusion Tensor Imaging; Prognosis; Saimiri; Spinal Cord; Spinal Cord Injuries; White Matter
PubMed: 33057016
DOI: 10.1038/s41598-020-74234-2 -
The Anatomical Record Jan 1983The morphology of spinal cord in the caudal-most spinal segments of normal adult Sternarchus albifrons is different from that of more rostral adult cord. The caudal... (Comparative Study)
Comparative Study
The morphology of spinal cord in the caudal-most spinal segments of normal adult Sternarchus albifrons is different from that of more rostral adult cord. The caudal segments are strikingly similar to the regenerating spinal cord observed after amputation of the tail in Sternarchus. In the caudal-most vertebral segment of normal spinal cord, ependymal cells are radially enlarged and are more numerous than in more rostral adult cord. Large processes of the ependymal cells extend into the central canal, which also contains a prominent Reissner's fiber. Invaginations of the outer surface of the spinal cord, with the associated basal lamina, are common. Lateral to the immediate ependymal layer, extracellular spaces contain longitudinally oriented neurites. Cell bodies and cell processes filled with dense-cored vesicles occur throughout the caudal-most segment of spinal cord, and are especially concentrated in the ventral half, interspersed with numerous capillaries. In all these respects the caudal-most segments of normal adult spinal cord in Sternarchus closely resemble regenerating spinal cord of Sternarchus. In both regions, at least some of the ependymal cells retain the ability to divide and generate new neurons and glial cells.
Topics: Animals; Ependyma; Fishes; Nerve Regeneration; Spinal Cord; Tail
PubMed: 6837938
DOI: 10.1002/ar.1092050111 -
PloS One 2016Despite the continuous improvement in medical imaging technology, visualizing the spinal cord poses severe problems due to structural or incidental causes, such as small...
Despite the continuous improvement in medical imaging technology, visualizing the spinal cord poses severe problems due to structural or incidental causes, such as small access space and motion artifacts. In addition, positional guidance on the spinal cord is not commonly available during surgery, with the exception of neuronavigation techniques based on static pre-surgical data and of radiation-based methods, such as fluoroscopy. A fast, bedside, intraoperative real-time imaging, particularly necessary during the positioning of endoscopic probes or tools, is an unsolved issue. The objective of our work, performed on experimental rats, is to demonstrate potential intraoperative spinal cord imaging and probe guidance by optical coherence tomography (OCT). Concurrently, we aimed to demonstrate that the electromagnetic OCT irradiation exerted no particular effect at the neuronal and synaptic levels. OCT is a user-friendly, low-cost and endoscopy-compatible photonics-based imaging technique. In particular, by using a Fourier-domain OCT imager, operating at 850 nm wavelength and scanning transversally with respect to the spinal cord, we have been able to: 1) accurately image tissue structures in an animal model (muscle, spine bone, cerebro-spinal fluid, dura mater and spinal cord), and 2) identify the position of a recording microelectrode approaching and inserting into the cord tissue 3) check that the infrared radiation has no actual effect on the electrophysiological activity of spinal neurons. The technique, potentially extendable to full three-dimensional image reconstruction, shows prospective further application not only in endoscopic intraoperative analyses and for probe insertion guidance, but also in emergency and adverse situations (e.g. after trauma) for damage recognition, diagnosis and fast image-guided intervention.
Topics: Animals; Male; Rats; Rats, Sprague-Dawley; Spinal Cord; Tomography, Optical Coherence
PubMed: 27050096
DOI: 10.1371/journal.pone.0152539 -
AJR. American Journal of Roentgenology Sep 1995Prior to the advent of MR imaging, the internal architecture of the spinal cord could not be directly imaged. The solution of many technical problems (e.g., respiratory... (Review)
Review
Prior to the advent of MR imaging, the internal architecture of the spinal cord could not be directly imaged. The solution of many technical problems (e.g., respiratory motion, cardiac and CSF pulsation, inadequate spatial resolution) has provided the opportunity for an increasingly refined analysis of intramedullary lesions. This article begins with a brief review of the results of high-resolution MR imaging studies of the cadaveric spinal cord. The article then focuses on MR imaging in the diagnosis of intramedullary diseases that involve specific neural pathways or vascular territories. Lesions are categorized as degenerative, inflammatory, traumatic, or ischemic. These diseases generally have distinctive clinical findings that reflect dysfunction of particular ascending sensory tracts or descending motor tracts. The corresponding abnormalities on MR images reflect the pathologic changes that occur in the affected neural pathways. Knowledge of the appearance of these diseases on MR images allows the formation of a narrow differential diagnosis and, in many cases, the confident exclusion of neoplasm as the cause of myelopathy.
Topics: Humans; Magnetic Resonance Imaging; Neural Pathways; Spinal Cord; Spinal Cord Diseases
PubMed: 7645462
DOI: 10.2214/ajr.165.3.7645462 -
Journal of Theoretical Biology Jan 2018The study of indeterminate-growing organisms such as teleost fish presents a unique opportunity for improving our understanding of central nervous tissue growth during...
The study of indeterminate-growing organisms such as teleost fish presents a unique opportunity for improving our understanding of central nervous tissue growth during adulthood. Integrating the existing experimental data associated with this process into a theoretical framework through mathematical or computational modeling provides further research avenues through sensitivity analysis and optimization. While this type of approach has been used extensively in investigations of tumor growth, wound healing, and bone regeneration, the development of nervous tissue has been rarely studied within a modeling framework. To address this gap, the present work introduces a distributed model of spinal cord growth in the knifefish Apteronotus leptorhynchus, an established teleostean model of adult growth in the central nervous system. The proposed model incorporates two mechanisms, cell proliferation by active stem/progenitor cells and cell drift due to population pressure, both of which are subject to global constraints. A coupled reaction-diffusion equation approach was adopted to represent the densities of actively-proliferating and non-proliferating cells along the longitudinal axis of the spinal cord. Computer simulations using this model yielded biologically-feasible growth trajectories. Subsequent comparisons with whole-organism growth curves allowed the estimation of previously-unknown parameters, such as relative growth rates.
Topics: Algorithms; Animals; Cell Proliferation; Computer Simulation; Gymnotiformes; Models, Biological; Spinal Cord; Time Factors
PubMed: 29031516
DOI: 10.1016/j.jtbi.2017.10.012