scholarly journals Comparison of in vivo and ex vivo viscoelastic behavior of the spinal cord

2018 ◽  
Vol 68 ◽  
pp. 78-89 ◽  
Author(s):  
Nicole L. Ramo ◽  
Snehal S. Shetye ◽  
Femke Streijger ◽  
Jae H.T. Lee ◽  
Kevin L. Troyer ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Ex Vivo ◽  
Viscoelastic Behavior

scholarly journals Bone Metastasis Pain, from the Bench to the Bedside

2019 ◽  
Vol 20 (2) ◽  
pp. 280 ◽  
Author(s):  
Federica Aielli ◽  
Marco Ponzetti ◽  
Nadia Rucci
Keyword(s):  
Spinal Cord ◽  
Bone Metastasis ◽  
Bone Fractures ◽  
Ex Vivo ◽  
Life Quality ◽  
Cord Compression ◽  
Cellular Mechanisms ◽  
Oncologic Patients ◽  
Virtuous Cycle

Bone is the most frequent site of metastasis of the most common cancers in men and women. Bone metastasis incidence has been steadily increasing over the years, mainly because of higher life expectancy in oncologic patients. Although bone metastases are sometimes asymptomatic, their consequences are most often devastating, impairing both life quality and expectancy, due to the occurrence of the skeletal-related events, including bone fractures, hypercalcemia and spinal cord compression. Up to 75% of patients endure crippling cancer-induced bone pain (CIBP), against which we have very few weapons. This review’s purpose is to discuss the molecular and cellular mechanisms that lead to CIBP, including how cancer cells convert the bone “virtuous cycle” into a cancer-fuelling “vicious cycle”, and how this leads to the release of molecular mediators of pain, including protons, neurotrophins, interleukins, chemokines and ATP. Preclinical tests and assays to evaluate CIBP, including the incapacitance tester (in vivo), and neuron/glial activation in the dorsal root ganglia/spinal cord (ex vivo) will also be presented. Furthermore, current therapeutic options for CIBP are quite limited and nonspecific and they will also be discussed, along with up-and-coming options that may render CIBP easier to treat and let patients forget they are patients.

scholarly journals Dynamic CCN3 expression in the murine CNS does not confer essential roles in myelination or remyelination

2020 ◽  
Vol 117 (30) ◽  
pp. 18018-18028
Author(s):  
Nira de la Vega Gallardo ◽  
Rosana Penalva ◽  
Marie Dittmer ◽  
Michelle Naughton ◽  
John Falconer ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Ex Vivo ◽  
Matricellular Protein ◽  
Suprachiasmatic Nuclei ◽  
Dynamic Expression ◽  
Ccn3 Expression ◽  
Cns Myelination

CCN3 is a matricellular protein that promotes oligodendrocyte progenitor cell differentiation and myelination in vitro and ex vivo. CCN3 is therefore a candidate of interest in central nervous system (CNS) myelination and remyelination, and we sought to investigate the expression and role of CCN3 during these processes. We found CCN3 to be expressed predominantly by neurons in distinct areas of the CNS, primarily the cerebral cortex, hippocampus, amygdala, suprachiasmatic nuclei, anterior olfactory nuclei, and spinal cord gray matter. CCN3 was transiently up-regulated following demyelination in the brain of cuprizone-fed mice and spinal cord lesions of mice injected with lysolecithin. However, CCN3−/−mice did not exhibit significantly different numbers of oligodendroglia or differentiated oligodendrocytes in the healthy or remyelinating CNS, compared to WT controls. These results suggest that despite robust and dynamic expression in the CNS, CCN3 is not required for efficient myelination or remyelination in the murine CNS in vivo.

Robot-assisted endoscopic exploration of the spinal cord

2010 ◽  
Vol 224 (7) ◽  
pp. 1515-1529 ◽  
Author(s):  
L Ascari ◽  
C Stefanini ◽  
U Bertocchi ◽  
P Dario
Keyword(s):  
Spinal Cord ◽  
Subarachnoid Space ◽  
Ex Vivo ◽  
Hierarchical Control ◽  
Three Dimensional ◽  
Robot Assisted ◽  
Actuation System ◽  
Spinal Subarachnoid Space

This work presents the design and development of an integrated image-guided robot-assisted endoscopic system for the safe navigation within the spinal subarachnoid space, providing the surgeon with the direct vision of the structures (i.e. spinal cord, roots, vessels) and the possibility of performing some particularly useful operations, like local electrostimulation of nerve roots. The modelling, micro-fabrication, fluidic sustentation, and cable-based actuation system of a steerable tip for a multilumen flexible catheter is described; the hierarchical control system shared between the surgeon and the computer, and based on machine vision techniques and a simple but effective three-dimensional reconstruction is detailed. The Blind Expected Perception sensory-motor scheme is proposed in robot-assited endoscopy. Results from in vitro, ex vivo, and in vivo experiments show that the described model can accurately predict the shape of the catheter given the tension distribution on the cables, that the proposed actuation system can assure smooth and precise control of the catheter tip, that the fluidic sustentation of the catheter is essential in in vivo navigation, and that the proposed rear view mirror interface to show non-visible obstacles is appropriate; in conclusion, the results proved the validity of the proposed solution to develop an intrinsically safe robotic system for navigation and intervention in a narrow and challenging environment such as the spinal subarachnoid space.

scholarly journals Calcium Imaging of Living Astrocytes in the Mouse Spinal Cord following Sensory Stimulation

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Giovanni Cirillo ◽  
Daniele De Luca ◽  
Michele Papa
Keyword(s):  
Spinal Cord ◽  
Cultured Cells ◽  
Ex Vivo ◽  
Sensory Stimulation ◽  
Widespread Application ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Heart Beating ◽  
Sensory Activity

Astrocytic Ca2+dynamics have been extensively studied inex vivomodels; however, the recent development of two-photon microscopy and astrocyte-specific labeling has allowed the study of Ca2+signaling in living central nervous system. Ca2+waves in astrocytes have been described in cultured cells and slice preparations, but evidence for astrocytic activation during sensory activity is lacking. There are currently few methods to image living spinal cord: breathing and heart-beating artifacts have impeded the widespread application of this technique. We here imaged the living spinal cord by two-photon microscopy in C57BL6/J mice. Through pressurized injection, we specifically loaded spinal astrocytes using the red fluorescent dye sulforhodamine 101 (SR101) and imaged astrocytic Ca2+levels with Oregon-Green BAPTA-1 (OGB). Then, we studied astrocytic Ca2+levels at rest and after right electrical hind paw stimulation. Sensory stimulation significantly increased astrocytic Ca2+levels within the superficial dorsal horn of the spinal cord compared to rest. In conclusion,in vivomorphofunctional imaging of living astrocytes in spinal cord revealed that astrocytes actively participate to sensory stimulation.

Lesion growth and degeneration patterns measured using diffusion tensor 9.4-T magnetic resonance imaging in rat spinal cord injury

2010 ◽  
Vol 13 (2) ◽  
pp. 181-192 ◽  
Author(s):  
Benjamin M. Ellingson ◽  
Brian D. Schmit ◽  
Shekar N. Kurpad
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Mr Imaging ◽  
Diffusion Tensor ◽  
Ex Vivo ◽  
Mean Diffusivity ◽  
Cavity Formation ◽  
Cord Injury ◽  
Lesion Growth

Object Using diffusion tensor MR imaging, the authors conducted a study to explore lesion growth and degeneration patterns, from the acute through chronic stages of spinal cord injury (SCI), in an experimental animal model. Methods In vivo and ex vivo diffusion tensor imaging was performed using a 9.4-T MR imaging system in rats allowed to recover from traumatic contusion SCI from 2 weeks through 25 weeks postinjury, mimicking progression of human SCI from the acute through chronic stages. Results Results showed significant growth of the traumatic lesion up to 15 weeks postinjury, where both the size and mean diffusivity (MD) reached a maximum that was maintained through the remainder of recovery. Mean diffusivity was sensitive to overall spinal cord integrity, whereas fractional anisotropy showed specificity to sites of cavity formation. The use of an MD contour map for in vivo data and a 3D surface map for ex vivo data, showing MD as a function of rostral-caudal distance and recovery time, allowed documentation of rostral and caudal spreading of the lesion. Conclusions Results from this study demonstrate changes in both lesion morphology and diffusivity beyond previously reported time points and provide a unique perspective on the process of cavity formation and degeneration following traumatic SCI. Additionally, results suggest that MD more accurately defines regions of histological damage than do regions of T2 signal hyperintensity. This could have significant clinical implications in the detection and potential treatment of posttraumatic syringes in SCI.

scholarly journals Histamine induces peripheral and central hypersensitivity to bladder distension via the histamine H1 receptor and TRPV1

2020 ◽  
Vol 318 (2) ◽  
pp. F298-F314 ◽  
Author(s):  
Luke Grundy ◽  
Ashlee Caldwell ◽  
Sonia Garcia Caraballo ◽  
Andelain Erickson ◽  
Gudrun Schober ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Transient Receptor Potential ◽  
Ex Vivo ◽  
Transient Receptor Potential Vanilloid ◽  
Receptor Subtypes ◽  
Urothelial Cells ◽  
Bladder Pain ◽  
Bladder Distension ◽  
Bladder Afferents

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a common chronic pelvic disorder with sensory symptoms of urinary urgency, frequency, and pain, indicating a key role for hypersensitivity of bladder-innervating sensory neurons. The inflammatory mast cell mediator histamine has long been implicated in IC/BPS, yet the direct interactions between histamine and bladder afferents remain unclear. In the present study, we show, using a mouse ex vivo bladder afferent preparation, that intravesical histamine enhanced the mechanosensitivity of subpopulations of afferents to bladder distension. Histamine also recruited “silent afferents” that were previously unresponsive to bladder distension. Furthermore, in vivo intravesical histamine enhanced activation of dorsal horn neurons within the lumbosacral spinal cord, indicating increased afferent signaling in the central nervous system. Quantitative RT-PCR revealed significant expression of histamine receptor subtypes ( Hrh1– Hrh3) in mouse lumbosacral dorsal root ganglia (DRG), bladder detrusor smooth muscle, mucosa, and isolated urothelial cells. In DRG, Hrh1 was the most abundantly expressed. Acute histamine exposure evoked Ca2+ influx in select populations of DRG neurons but did not elicit calcium transients in isolated primary urothelial cells. Histamine-induced mechanical hypersensitivity ex vivo was abolished in the presence of the histamine H1 receptor antagonist pyrilamine and was not present in preparations from mice lacking transient receptor potential vanilloid 1 (TRPV1). Together, these results indicate that histamine enhances the sensitivity of bladder afferents to distension via interactions with histamine H1 receptor and TRPV1. This hypersensitivity translates to increased sensory input and activation in the spinal cord, which may underlie the symptoms of bladder hypersensitivity and pain experienced in IC/BPS.

scholarly journals Cerebrospinal fluid drainage kinetics across the cribriform plate are reduced with aging

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Molly Brady ◽  
Akib Rahman ◽  
Abigail Combs ◽  
Chethana Venkatraman ◽  
R. Tristan Kasper ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Subarachnoid Space ◽  
Ex Vivo ◽  
Cribriform Plate ◽  
Cervical Lymph Nodes ◽  
Spinal Subarachnoid Space ◽  
Ex Vivo Tissues ◽  
The Brain

Abstract Background Continuous circulation and drainage of cerebrospinal fluid (CSF) are essential for the elimination of CSF-borne metabolic products and neuronal function. While multiple CSF drainage pathways have been identified, the significance of each to normal drainage and whether there are differential changes at CSF outflow regions in the aging brain are unclear. Methods Dynamic in vivo imaging of near infrared fluorescently-labeled albumin was used to simultaneously visualize the flow of CSF at outflow regions on the dorsal side (transcranial and -spinal) of the central nervous system. This was followed by kinetic analysis, which included the elimination rate constants for these regions. In addition, tracer distribution in ex vivo tissues were assessed, including the nasal/cribriform region, dorsal and ventral surfaces of the brain, spinal cord, cranial dura, skull base, optic and trigeminal nerves and cervical lymph nodes. Results Based on the in vivo data, there was evidence of CSF elimination, as determined by the rate of clearance, from the nasal route across the cribriform plate and spinal subarachnoid space, but not from the dorsal dural regions. Using ex vivo tissue samples, the presence of tracer was confirmed in the cribriform area and olfactory regions, around pial blood vessels, spinal subarachnoid space, spinal cord and cervical lymph nodes but not for the dorsal dura, skull base or the other cranial nerves. Also, ex vivo tissues showed retention of tracer along brain fissures and regions associated with cisterns on the brain surfaces, but not in the brain parenchyma. Aging reduced CSF elimination across the cribriform plate but not that from the spinal SAS nor retention on the brain surfaces. Conclusions Collectively, these data show that the main CSF outflow sites were the nasal region across the cribriform plate and from the spinal regions in mice. In young adult mice, the contribution of the nasal and cribriform route to outflow was much higher than from the spinal regions. In older mice, the contribution of the nasal route to CSF outflow was reduced significantly but not for the spinal routes. This kinetic approach may have significance in determining early changes in CSF drainage in neurological disorder, age-related cognitive decline and brain diseases.

scholarly journals Blood vessels guide Schwann cell migration in the adult demyelinated CNS through Eph/ephrin signaling

2018 ◽  
Author(s):  
Beatriz Garcia-Diaz ◽  
Corinne Bachelin ◽  
Fanny Coulpier ◽  
Gaspard Gerschenfeld ◽  
Cyrille Deboux ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Blood Vessel ◽  
Ex Vivo ◽  
Migration Route ◽  
Eph Receptors ◽  
The Central Nervous System ◽  
Vessel Network ◽  
First Time

ABSTRACTSchwann cells (SC) enter the central nervous system (CNS) in pathophysiological conditions. However, how SC invade the CNS to remyelinate central axons remains undetermined. We studied SC migratory behaviorex vivoandin vivoafter exogenous transplantation in the demyelinated spinal cord. Data highlight for the first time that SC migrate preferentially along blood vessel in perivascular ECM, avoiding CNS myelin. We demonstratein vitroandin vivothat this migration route occurs by virtue of a dual mode of action of Eph/ephrin receptor. Indeed, EphrinB3, enriched in myelin, interacts with SC Eph receptors, to drive SC away from CNS myelin, and triggers their preferential adhesion to ECM components, such as fibronectin via integrinβ1 interactions. This complex interplay enhances SC migration along the blood vessel network and together with lesion-induced vascular remodeling facilitates their timely invasion of the lesion site. These novel findings elucidate the mechanism by which SC invade and contribute to spinal cord repair.

scholarly journals Spinal cord dopamine D2/D3 receptors: in vivo and ex vivo imaging in the rat using 18F/11C-fallypride

2014 ◽  
Vol 41 (10) ◽  
pp. 841-847 ◽  
Author(s):  
Jasmeet Kaur ◽  
Armen Khararjian ◽  
Robert A. Coleman ◽  
Cristian C. Constantinescu ◽  
Min-Liang Pan ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Ex Vivo ◽  
D3 Receptors ◽  
Dopamine D2 ◽  
Ex Vivo Imaging

scholarly journals In vivo assessment of spinal cord elasticity using shear wave ultrasound in dogs

2018 ◽  
Vol 29 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Amro Al-Habib ◽  
Abdulrahman Albakr ◽  
Abdullah Al Towim ◽  
Metab Alkubeyyer ◽  
Abdullah Abu Jamea ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Shear Wave ◽  
Dura Mater ◽  
Ex Vivo ◽  
Shear Wave Elastography ◽  
Biomechanical Properties ◽  
Tissue Elasticity ◽  
Pia Mater ◽  
Balloon Compression

OBJECTIVEEvaluation of living tissue elasticity has wide applications in disease characterization and prognosis prediction. Few previous ex vivo attempts have been made to characterize spinal cord elasticity (SCE). Recently, tissue elasticity assessment has been clinically feasible using ultrasound shear wave elastography (SWE). The current study aims to characterize SCE in healthy dogs, in vivo, utilizing SWE, and to address SCE changes during compression.METHODSTen Greyhound dogs (mean age 14 months; mean weight 14.3 kg) were anesthetized and tracheally intubated, with hemodynamic and neurological monitoring. A 3-level, midcervical laminectomy was performed. SCE was assessed at baseline. Next, 8- and 13-mm balloon compressions were sequentially applied ventral to the spinal cord.RESULTSThe mean SCE was 18.5 ± 7 kPa. Elasticity of the central canal, pia mater, and dura mater were 21.7 ± 9.6 kPa, 26.1 ± 14.8 kPa, and 63.2 ± 11.5 kPa, respectively. As expected, the spinal cord demonstrated less elasticity than the dura mater (p < 0.0001) and pia mater (trend toward significance p = 0.08). Notably, the 13-mm balloon compression resulted in a stiffer spinal cord than at baseline (233 ± 73 kPa versus 18.5 ± 7 kPa, p < 0.0001) and 8-mm balloon compression (233 ± 73 kPa versus 185 ± 68 kPa, p < 0.048).CONCLUSIONSIn vivo SCE evaluation using SWE is feasible and comparable to earlier reports, as demonstrated by physical sectioning of the spinal cord. The compressed spinal cord is stiffer than a free spinal cord, with a linear increase in SCE with increasing mechanical compression. Knowledge of the biomechanical properties of the spinal cord including SCE has potential implications for disease management and prognosis.

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