Neurosurgery (Neuro Vascular)

Background: Blood breakdown products such as bilirubin and bilirubin oxidation products damage cortex and white matter after intracerebral hemorrhage(ICH). Here, we tested whether albumin can antagonize axonal damage caused by bilirubin. Methods: The effect of albumin on white matter injury was investigated using brain slices in vitro. After CD-1 mice brain slices were cut using a vibratome, they were incubated in one of five solutions: artificial cerebral spinal fluid (ACSF), bilirubin ACSF, bilirubin and albumin ACSF, bilirubin ACSF that had albumin added 1 hour(h) later, and bilirubin and denatured albumin ACSF. All solutions were continuously aerated with 95% O2 and 5% CO2. Subsequently, electrophysiological recordings of axonal response to electrical stimulation were performed 8h after incubation of brain slices. Results: Bilirubin treatment profoundly damaged both myelinated and unmeylinated axons in brain slices, but had a greater effect on myelinated axons. Unmyelinated axons were found to be more susceptible to damage from denatured albumin. Albumin treatment at 0 h and 1 h significantly diminished bilirubin toxicity for both myelinated and unmyelinated axons, with 1 h delayed albumin treatment conferring greater neuroprotection. Conclusions: These results implicate the role of albumin in preventing bilirubin-induced axonal damage following ICH and its potential therapeutic value for hemorrhagic stroke.

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Bilirubin and its Oxidation Products Damage Brain White Matter

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2014.154 ◽

2014 ◽

Vol 34 (11) ◽

pp. 1837-1847 ◽

Cited By ~ 21

Author(s):

Katarina Lakovic ◽

Jinglu Ai ◽

Josephine D'Abbondanza ◽

Asma Tariq ◽

Mohammed Sabri ◽

...

Keyword(s):

White Matter ◽

Dimethyl Sulfoxide ◽

Brain Slices ◽

Structure And Function ◽

Adult Brain ◽

Oxidation Products ◽

Unmyelinated Axons ◽

And Function

Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke.

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Chronic neocortical epileptogenesis in vitro

Journal of Neurophysiology ◽

10.1152/jn.1994.71.5.1762 ◽

1994 ◽

Vol 71 (5) ◽

pp. 1762-1773 ◽

Cited By ~ 91

Author(s):

S. N. Hoffman ◽

P. A. Salin ◽

D. A. Prince

Keyword(s):

White Matter ◽

Current Source ◽

Nmda Receptor Antagonist ◽

White Matter Injury ◽

Posttraumatic Epilepsy ◽

Layer V ◽

Vitro Model ◽

Interictal Discharges ◽

Interictal Discharge

1. We used an in vitro model to explore critical aspects of chronic epileptogenesis. Partial neocortical isolations having intact blood supply were made in rat and guinea pig from postnatal day 7 to 34 and then examined 1 to 150 days later in standard brain slice preparations. 2. The epileptogenic potential of several different types of lesions was assessed. Slices containing transcortical (i.e., gray matter) lesions, with or without a contiguous white matter injury (i.e., “undercut”), developed chronic epileptogenesis after a latency of approximately 1–2 wk, manifested by evoked and spontaneous “interictal” discharges and evoked “ictal” events. The region of hyperexcitability did not extend beyond approximately 2 mm from the chronic transcortical lesion and was rarely observed in slices having only an apparent white matter injury. 3. Multiple recordings and current source density (CSD) analysis identified layer V as the source of the interictal discharge. 4. Significant differences in CSD profiles of the evoked interictal discharge occurred between chronically epileptogenic slices and control (noninjured) slices bathed in the convulsant, bicuculline methiodide, suggesting that mechanisms other than disinhibition must be involved in posttraumatic epileptogenesis. 5. Interictal events were blocked in most but not all chronically injured slices by application of the N-methyl-D-aspartate (NMDA) receptor antagonist D-2-amino-5-phosphonovalerate (D-AP5), suggesting that non-NMDA receptors were predominantly involved in some preparations. 6. This model of chronic epileptogenesis in vitro will be useful in studies relevant to mechanisms of posttraumatic epilepsy in man.

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Glutamate receptors: the cause or cure in perinatal white matter injury?

Neuron Glia Biology ◽

10.1017/s1740925x11000147 ◽

2010 ◽

Vol 6 (4) ◽

pp. 209-211 ◽

Cited By ~ 2

Author(s):

R. Douglas Fields

Keyword(s):

White Matter ◽

Glutamate Receptors ◽

Metabotropic Glutamate Receptors ◽

Experimental Studies ◽

Perinatal Period ◽

White Matter Injury ◽

Glutamate Toxicity ◽

Diffuse White Matter ◽

Group I

Glutamate toxicity from hypoxia-ischaemia during the perinatal period causes white matter injury that can result in long-term motor and intellectual disability. Blocking ionotropic glutamate receptors (GluRs) has been shown to inhibit oligodendrocyte injury in vitro, but GluR antagonists have not yet proven helpful in clinical studies. The opposite approach of activating GluRs on developing oligodendrocytes shows promise in experimental studies on rodents as reported by Jartzie et al., in this issue. Group I metabotropic glutamate receptors (mGluRs) are expressed transiently on developing oligodendrocytes in humans during the perinatal period, and the blood–brain-barrier permeable agonist of group I mGluRs, 1-aminocyclopentane-trans-1,3-dicarboxylic acid (ACPD), reduces white matter damage significantly in a rat model of perinatal hypoxia-ischaemia. The results suggest drugs activating this class of GluRs could provide a new therapeutic approach for preventing cerebral palsy and other neurological consequences of diffuse white matter injury in premature infants.

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Transplanted Oligodendrocyte Progenitor Cells Survive in the Brain of a Rat Neonatal White Matter Injury Model but Less Mature in Comparison with the Normal Brain

Cell Transplantation ◽

10.1177/0963689720946092 ◽

2020 ◽

Vol 29 ◽

pp. 096368972094609

Author(s):

Shino Ogawa ◽

Mutsumi Hagiwara ◽

Sachiyo Misumi ◽

Naoki Tajiri ◽

Takeshi Shimizu ◽

...

Keyword(s):

White Matter ◽

Replacement Therapy ◽

Fluorescent Protein ◽

White Matter Injury ◽

Normal Brain ◽

Cell Replacement Therapy ◽

Cell Replacement ◽

Vitro Effect ◽

The Brain

Preterm infants have a high risk of neonatal white matter injury (WMI) caused by hypoxia-ischemia. Cell-based therapies are promising strategies for neonatal WMI by providing trophic substances and replacing lost cells. Using a rat model of neonatal WMI in which oligodendrocyte progenitors (OPCs) are predominantly damaged, we investigated whether insulin-like growth factor 2 (IGF2) has trophic effects on OPCs in vitro and whether OPC transplantation has potential as a cell replacement therapy. Enhanced expression of Igf2 mRNA was first confirmed in the brain of P5 model rats by real-time polymerase chain reaction. Immunostaining for IGF2 and its receptor IGF2 R revealed that both proteins were co-expressed in OLIG2-positive and GFAP-positive cells in the corpus callosum (CC), indicating autocrine and paracrine effects of IGF2. To investigate the in vitro effect of IGF2 on OPCs, IGF2 (100 ng/ml) was added to the differentiation medium containing ciliary neurotrophic factor (10 ng/ml) and triiodothyronine (20 ng/ml), and IGF2 promoted the differentiation of OPCs into mature oligodendrocytes. We next transplanted rat-derived OPCs that express green fluorescent protein into the CC of neonatal WMI model rats without immunosuppression and investigated the survival of grafted cells for 8 weeks. Although many OPCs survived for at least 8 weeks, the number of mature oligodendrocytes was unexpectedly small in the CC of the model compared with that in the sham-operated control. These findings suggest that the mechanism in the brain that inhibits differentiation should be solved in cell replacement therapy for neonatal WMI as same as trophic support from IGF2.

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Live Computerized Videomicroscopy of Cerebral Microvessels in Brain Slices

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1993.86 ◽

1993 ◽

Vol 13 (4) ◽

pp. 676-682 ◽

Cited By ~ 21

Author(s):

Oren Sagher ◽

Xi-Qing Zhang ◽

Wilson Szeto ◽

Quoc Anh Thai ◽

Yongcheng Jin ◽

...

Keyword(s):

Water Immersion ◽

Brain Slices ◽

Model System ◽

Additional Advantage ◽

Cerebral Microvessels ◽

Electrophysiological Recordings ◽

Artificial Cerebrospinal Fluid ◽

Vascular Elements ◽

Cerebral Microvasculature

A model system for studying cerebral microvasculature is presented in which submerged in vitro brain slices are examined by computerized videomicroscopy. Brain slices are superfused continuously with artificial cerebrospinal fluid, while blood vessels are monitored using a transmission light microscope with water immersion objectives. The responses to well-characterized vasoactive compounds indicate that basic physiological characteristics are maintained in this preparation. This model system represents a simple and rapid technique for studying cerebrovascular responses under conditions in which vessels are surrounded by their normal cellular microenvironment. An additional advantage of this technique is the ability to perform simultaneous electrophysiological recordings in identified neurons. This will facilitate the study of interactions between neuronal and vascular elements and may help elucidate mechanisms underlying the local regulation of cerebral microvasculature.

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Axonal degeneration in an in vitro model of ischemic white matter injury

Neurobiology of Disease ◽

10.1016/j.nbd.2019.104672 ◽

2020 ◽

Vol 134 ◽

pp. 104672 ◽

Cited By ~ 3

Author(s):

Yuexian Cui ◽

Xuelian Jin ◽

Dong-Joo Choi ◽

Jun Young Choi ◽

Hyung Soon Kim ◽

...

Keyword(s):

White Matter ◽

In Vitro Model ◽

Axonal Degeneration ◽

White Matter Injury ◽

Vitro Model

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HDAC inhibition reduces white matter injury after intracerebral hemorrhage

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x20942613 ◽

2020 ◽

pp. 0271678X2094261

Author(s):

Heng Yang ◽

Wei Ni ◽

Pengju Wei ◽

Sicheng Li ◽

Xinjie Gao ◽

...

Keyword(s):

White Matter ◽

Intracerebral Hemorrhage ◽

Hdac Inhibitor ◽

Histone Deacetylases ◽

Macrophage Polarization ◽

Conditional Knockout ◽

White Matter Injury ◽

Hdac Inhibition

Inhibition of histone deacetylases (HDACs) has been shown to reduce inflammation and white matter damage after various forms of brain injury via modulation of microglia/macrophage polarization. Previously we showed that the HDAC inhibitor scriptaid could attenuate white matter injury (WMI) after ICH. To access whether modulation of microglia/macrophage polarization might underlie this protection, we investigated the modulatory role of HDAC2 in microglia/macrophage polarization in response to WMI induced by intracerebral hemorrhage (ICH) and in primary microglia and oligodendrocyte co-cultures. HDAC2 activity was inhibited via conditional knockout of the Hdac2 gene in microglia or via administration of scriptaid. Conditional knockout of the Hdac2 gene in microglia and HDAC inhibition with scriptaid both improved neurological functional recovery and reduced WMI after ICH. Additionally, HDAC inhibition shifted microglia/macrophage polarization toward the M2 phenotype and reduced proinflammatory cytokine secretion after ICH in vivo. In vitro, a transwell co-culture model of microglia and oligodendrocytes also demonstrated that the HDAC inhibitor protected oligodendrocytes by modulating microglia polarization and mitigating neuroinflammation. Moreover, we found that scriptaid decreased the expression of pJAK2 and pSTAT1 in cultured microglia when stimulated with hemoglobin. Thus, HDAC inhibition ameliorated ICH-mediated neuroinflammation and WMI by modulating microglia/macrophage polarization.

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Integration of autopatching with automated pipette and cell detection in vitro

Journal of Neurophysiology ◽

10.1152/jn.00386.2016 ◽

2016 ◽

Vol 116 (4) ◽

pp. 1564-1578 ◽

Cited By ~ 22

Author(s):

Qiuyu Wu (吴秋雨) ◽

Ilya Kolb ◽

Brendan M. Callahan ◽

Zhaolun Su ◽

William Stoy ◽

...

Keyword(s):

Computer Vision ◽

Cell Membrane ◽

Patch Clamp ◽

Brain Slices ◽

Cell Detection ◽

Trial Duration ◽

Electrophysiological Recordings ◽

Main Technique ◽

Simplex Virus

Patch clamp is the main technique for measuring electrical properties of individual cells. Since its discovery in 1976 by Neher and Sakmann, patch clamp has been instrumental in broadening our understanding of the fundamental properties of ion channels and synapses in neurons. The conventional patch-clamp method requires manual, precise positioning of a glass micropipette against the cell membrane of a visually identified target neuron. Subsequently, a tight “gigaseal” connection between the pipette and the cell membrane is established, and suction is applied to establish the whole cell patch configuration to perform electrophysiological recordings. This procedure is repeated manually for each individual cell, making it labor intensive and time consuming. In this article we describe the development of a new automatic patch-clamp system for brain slices, which integrates all steps of the patch-clamp process: image acquisition through a microscope, computer vision-based identification of a patch pipette and fluorescently labeled neurons, micromanipulator control, and automated patching. We validated our system in brain slices from wild-type and transgenic mice expressing channelrhodopsin 2 under the Thy1 promoter (line 18) or injected with a herpes simplex virus-expressing archaerhodopsin, ArchT. Our computer vision-based algorithm makes the fluorescent cell detection and targeting user independent. Compared with manual patching, our system is superior in both success rate and average trial duration. It provides more reliable trial-to-trial control of the patching process and improves reproducibility of experiments.

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Inhibition of Mitochondrial ROS by MitoQ Alleviates White Matter Injury and Improves Outcomes after Intracerebral Haemorrhage in Mice

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/8285065 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Weixiang Chen ◽

Chao Guo ◽

Zhengcai Jia ◽

Jie Wang ◽

Min Xia ◽

...

Keyword(s):

White Matter ◽

Intracerebral Haemorrhage ◽

Motor Evoked Potential ◽

White Matter Injury ◽

Antioxidant Treatment ◽

Evidence Based Treatment ◽

Mitochondrial Ros ◽

Ros Scavenger ◽

Oligodendrocyte Precursor

White matter injury (WMI) is an important cause of high disability after intracerebral haemorrhage (ICH). It is widely accepted that reactive oxygen species (ROS) contributes to WMI, but there is still no evidence-based treatment. Here, mitoquinone (MitoQ), a newly developed selective mitochondrial ROS scavenger, was used to test its neuroprotective potential. The data showed that MitoQ attenuated motor function deficits and motor-evoked potential (MEP) latency prolongation. Further research found that MitoQ blunted the loss of oligodendrocytes and oligodendrocyte precursor cells, therefore reduced demyelination and axon swelling after ICH. In the in vitro experiments, MitoQ, but not the nonselective antioxidant, almost completely attenuated the iron-induced membrane potential decrease and cell death. Mechanistically, MitoQ blocked the ATP deletion and mitochondrial ROS overproduction. The present study demonstrates that the selective mitochondrial ROS scavenger MitoQ may improve the efficacy of antioxidant treatment of ICH by white matter injury alleviation.

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Ceria Nanoparticles Ameliorate White Matter Injury After Intracerebral Hemorrhage: Microglia-astrocyte Involvement in Remyelination

10.21203/rs.3.rs-86014/v1 ◽

2020 ◽

Author(s):

Jingwei Zheng ◽

Jia‘nan Lu ◽

Shuhao Mei ◽

Haijian Wu ◽

Zeyu Sun ◽

...

Keyword(s):

White Matter ◽

Intracerebral Hemorrhage ◽

Molecular Mechanisms ◽

White Matter Injury ◽

Ceria Nanoparticles ◽

Ros Scavenging ◽

Transmission Electron Microscopy Analysis ◽

Positive Effects ◽

Myelin Debris

Abstract Background: Intracerebral hemorrhage (ICH) can induce excess accumulation of reactive oxygen species (ROS) and subsequently cause severe white matter injury. The process of oligodendrocyte progenitor cell (OPC) differentiation is orchestrated by microglia and astrocytes, and ROS also drives the activation of microglia and astrocytes. In light of the potent ROS scavenging capacity of ceria nanoparticles (CeNP), we aimed to investigate whether treatment with CeNP ameliorates white matter injury by modulating ROS-induced microglial polarization and astrocyte alteration. Methods: ICH was induced in vivo by collagenase VII injection in mice. Mice were administered with PLX3397 for depleting microglia. Primary microglia and astrocytes were used for in vitro experiments. Transmission electron microscopy analysis and immunostaining were performed to verify the positive effects of CeNP in remyelination and OPC differentiation. Flow cytometry, real-time polymerase chain reaction, immunofluorescence and western blotting were used to detect microglia polarization, astrocytes alteration and the underlying molecular mechanisms.Results: CeNP treatment strongly inhibited ROS-induced NF-κB p65 translocation in both microglia and astrocytes, and significantly decreased the expression of M1 microglia and A1 astrocyte. Furthermore, we found that CeNP treatment promoted remyelination and OPC differentiation at 7 days and 21 days post ICH, and such effects were alleviated after microglial depletion. Interestingly, we also found that the number of mature oligodendrocytes was moderately enhanced in ICH + CeNP + PLX3397 treated mice compared to the ICH + Vehicle + PLX3397 group. Therefore, astrocytes might participate in the pathophysiological process. The subsequent phagocytosis assay indicated that A1 astrocyte highly expressed C3, which could bind with microglia C3aR and hinder microglial engulfment of myelin debris. This result further replenished the feedback mechanism from astrocytes to microglia. Conclusion: The present study reveals a new mechanism in white matter injury after ICH: ICH induces M1 microglia and A1 astrocyte through ROS-induced NF-κB p65 translocation that hinders OPC maturation. Subsequently, A1 astrocytes inhibit microglial phagocytosis of myelin debris via an astrocytic C3-microglial C3aR axis. Polyethylene glycol-CeNP treatment inhibits this pathological process and ultimately promotes remyelination. Such findings enlighten us that astrocytes and microglia should be regarded as a functional unit in future works.

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