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Seminars in Ultrasound, CT, and MR Oct 2023The spinal cord comprises the part of the central nervous system located within the vertebral canal, extending from the foramen magnum to approximately the second lumbar... (Review)
Review
The spinal cord comprises the part of the central nervous system located within the vertebral canal, extending from the foramen magnum to approximately the second lumbar vertebra. The spinal cord is covered by 3 meninges: dura mater, arachnoid mater, and pia mater (arranged from the outermost layer inward). A cross-section of the spinal cord reveals gray and white matter. Ascending and descending pathways have defined locations in the matter of the spinal cord. This article aims to review the spinal cord anatomy and demonstrate the imaging aspects, which are essential for the interpretation and understanding of spinal cord injuries.
Topics: Humans; Meninges; Dura Mater; Spinal Cord; Arachnoid; Pia Mater
PubMed: 37555687
DOI: 10.1053/j.sult.2023.03.011 -
Journal of Neurochemistry Aug 2023The central nervous system/peripheral nervous system (CNS/PNS) extracellular matrix is a dynamic and highly interactive space-filling, cell-supportive,... (Review)
Review
The central nervous system/peripheral nervous system (CNS/PNS) extracellular matrix is a dynamic and highly interactive space-filling, cell-supportive, matrix-stabilising, hydrating entity that creates and maintains tissue compartments to facilitate regional ionic micro-environments and micro-gradients that promote optimal neural cellular activity. The CNS/PNS does not contain large supportive collagenous and elastic fibrillar networks but is dominated by a high glycosaminoglycan content, predominantly hyaluronan (HA) and collagen is restricted to the brain microvasculature, blood-brain barrier, neuromuscular junction and meninges dura, arachnoid and pia mater. Chondroitin sulphate-rich proteoglycans (lecticans) interactive with HA have stabilising roles in perineuronal nets and contribute to neural plasticity, memory and cognitive processes. Hyaluronan also interacts with sialoproteoglycan associated with cones and rods (SPACRCAN) to stabilise the interphotoreceptor matrix and has protective properties that ensure photoreceptor viability and function is maintained. HA also regulates myelination/re-myelination in neural networks. HA fragmentation has been observed in white matter injury, multiple sclerosis, and traumatic brain injury. HA fragments (2 × 10 Da) regulate oligodendrocyte precursor cell maturation, myelination/remyelination, and interact with TLR4 to initiate signalling cascades that mediate myelin basic protein transcription. HA and its fragments have regulatory roles over myelination which ensure high axonal neurotransduction rates are maintained in neural networks. Glioma is a particularly invasive brain tumour with extremely high mortality rates. HA, CD44 and RHAMM (receptor for HA-mediated motility) HA receptors are highly expressed in this tumour. Conventional anti-glioma drug treatments have been largely ineffective and surgical removal is normally not an option. CD44 and RHAMM glioma HA receptors can potentially be used to target gliomas with PEP-1, a cell-penetrating HA-binding peptide. PEP-1 can be conjugated to a therapeutic drug; such drug conjugates have successfully treated dense non-operative tumours in other tissues, therefore similar applications warrant exploration as potential anti-glioma treatments.
Topics: Humans; Hyaluronic Acid; Extracellular Matrix Proteins; Extracellular Matrix; Collagen; Glioma; Central Nervous System; Tumor Microenvironment
PubMed: 37492973
DOI: 10.1111/jnc.15915 -
BioRxiv : the Preprint Server For... Aug 2023The recent characterization of the glymphatic system and meningeal lymphatics has re-emphasized the role of the meninges in facilitating CSF transport and clearance....
BACKGROUND
The recent characterization of the glymphatic system and meningeal lymphatics has re-emphasized the role of the meninges in facilitating CSF transport and clearance. Here, we characterize small and large CSF solute distribution patterns along the intracranial and surface meninges in neonatal rodents and compare our findings to a rodent model of intraventricular hemorrhage-posthemorrhagic hydrocephalus. We also examine CSF interactions with the tela choroidea and its pial invaginations into the choroid plexuses of the lateral, third, and fourth ventricles.
METHODS
1.9-nm gold nanoparticles, 15-nm gold nanoparticles, or 3 kDa Red Dextran Tetramethylrhodamine constituted in aCSF were infused into the right lateral ventricle of P7 rats to track CSF circulation. 10 minutes post-1.9-nm gold nanoparticle and Red Dextran Tetramethylrhodamine injection and 4 hours post-15-nm gold nanoparticle injection, animals were sacrificed and brains harvested for histologic analysis to identify CSF tracer localization in the cranial and spine meninges and choroid plexus. Spinal dura and leptomeninges (arachnoid and pia) wholemounts were also performed.
RESULTS
There was significantly less CSF tracer distribution in the dura compared to the arachnoid and pia maters in neonatal rodents. Both small and large CSF tracers were transported intracranially to the arachnoid and pia mater of the perimesencephalic cisterns and tela choroidea, but not the dura mater of the falx cerebri. CSF tracers followed a similar distribution pattern in the spinal meninges. In the choroid plexus, there was large CSF tracer distribution in the apical surface of epithelial cells, and small CSF tracer along the basolateral surface. There were no significant differences in tracer intensity in the intracranial meninges of control vs. intraventricular hemorrhage-posthemorrhagic hydrocephalus (PHH) rodents, indicating preserved meningeal transport in the setting of PHH.
CONCLUSIONS
Differential CSF tracer handling by the leptomeninges suggests that there are distinct roles for CSF handling between the arachnoid-pia and dura maters in the developing brain. Similarly, differences in apical vs. luminal choroid plexus CSF handling may provide insight into particle-size dependent CSF transport at the CSF-choroid plexus border.
PubMed: 37645776
DOI: 10.1101/2023.08.10.552826 -
Animals : An Open Access Journal From... Feb 2024Meningitis is the inflammation of the membranes surrounding the central nervous system and is poorly described in water buffaloes. Five cases of meningitis in adults...
Meningitis is the inflammation of the membranes surrounding the central nervous system and is poorly described in water buffaloes. Five cases of meningitis in adults buffaloes of the Murrah and Mediterranean breads were studied. All buffaloes came from a farm located in the municipality of Castanhal, Pará, Brazil at different times. Clinical examination showed neurological clinical signs, such as apathy, reluctance to move, spastic paresis especially of the pelvic limbs, hypermetria, difficulty getting up, pressing of the head into obstacles and convulsion. In three buffaloes, a large part of the horn had been lost, exposing the corresponding frontal sinus, through which a bloody to purulent exudate flowed. The hemogram revealed neutrophilic leukocytosis. At necropsy, adherence of the dura mater to the periosteum and a purulent to fibrinopurulent exudate were observed in the sulci of the cerebral cortex and on the pia mater over almost the entire surface of the brain and throughout the spinal cord. The cerebrospinal fluid had a cloudy aspect with fibrin filaments. The histopathology of buffaloes confirmed the diagnosis of bacterial fibrinopurulent meningitis. Buffaloes are susceptible to bacterial inflammation of the meninges due to fractures of the base of the horn and mostly present with neurological manifestations.
PubMed: 38338148
DOI: 10.3390/ani14030505 -
Cells Sep 2023Immune cells play a critical role in promoting neuroinflammation and the development of neuropathic pain. However, some subsets of immune cells are essential for pain...
Immune cells play a critical role in promoting neuroinflammation and the development of neuropathic pain. However, some subsets of immune cells are essential for pain resolution. Among them are regulatory T cells (Tregs), a specialised subpopulation of T cells that limit excessive immune responses and preserve immune homeostasis. In this study, we utilised intrathecal adoptive transfer of activated Tregs in male and female mice after peripheral nerve injury to investigate Treg migration and whether Treg-mediated suppression of pain behaviours is associated with changes in peripheral immune cell populations in lymphoid and meningeal tissues and spinal microglial and astrocyte reactivity and phenotypes. Treatment with Tregs suppressed mechanical pain hypersensitivity and improved changes in exploratory behaviours after chronic constriction injury (CCI) of the sciatic nerve in both male and female mice. The injected Treg cells were detected in the choroid plexus and the pia mater and in peripheral lymphoid organs in both male and female recipient mice. Nonetheless, Treg treatment resulted in differential changes in meningeal and lymph node immune cell profiles in male and female mice. Moreover, in male mice, adoptive transfer of Tregs ameliorated the CCI-induced increase in microglia reactivity and inflammatory phenotypic shift, increasing M2-like phenotypic markers and attenuating astrocyte reactivity and neurotoxic astrocytes. Contrastingly, in CCI female mice, Treg injection increased astrocyte reactivity and neuroprotective astrocytes. These findings show that the adoptive transfer of Tregs modulates meningeal and peripheral immunity, as well as spinal glial populations, and alleviates neuropathic pain, potentially through different mechanisms in males and females.
Topics: Mice; Male; Female; Animals; T-Lymphocytes, Regulatory; Hyperalgesia; Neuralgia; Spinal Cord; Meninges
PubMed: 37759539
DOI: 10.3390/cells12182317