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Spreading depolarization

Cèlia Sintas, Noèlia Fernàndez-Castillo, Marta Vila-Pueyo, Patricia Pozo-Rosich, Alfons Macaya, Bru Cormand
: Migraine with aura is a subtype of migraine consisting of neurological disturbances that usually precede headache. Cortical spreading depression (CSD) is the likely pathophysiological correlate of the aura phase of migraine, found in common and rare forms of migraine, such as familial hemiplegic migraine (FHM). CSD is a depolarization wave that propagates across the cerebral gray matter transiently suppressing neuronal activity. Prophylactic treatments for migraine, such as topiramate (TPM) or valproate (VPA), reduce the number of CSD events...
December 2, 2016: Journal of Pain: Official Journal of the American Pain Society
Rashika N Karunasinghe, Angus C Grey, Ravindra Telang, Srdjan M Vlajkovic, Janusz Lipski
Anoxic depolarization (AD) is an acute event evoked by brain ischemia, involving a profound loss of cell membrane potential and swelling that spreads over susceptible parts of the gray matter. Its occurrence is a strong predictor of the severity of neuronal injury. Little is known about this event in the Substantia Nigra, a midbrain nucleus critical for motor control. We tested the effects of oxygen and glucose deprivation (OGD), an in vitro model of brain ischemia, in rat midbrain slices. AD developed within 4min from OGD onset and spread in the Substantia Nigra pars reticulata (SNr), but not through the Substantia Nigra pars compacta (SNc)...
November 5, 2016: Neuroscience
Kristi J Warren, Samantha M Simet, Jacqueline A Pavlik, Jane M DeVasure, Joseph H Sisson, Jill A Poole, Todd A Wyatt
Alcohol-use disorders (AUD) persist in the United States and are heavily associated with an increased susceptibility to respiratory viral infections. Respiratory syncytial virus (RSV) in particular has received attention as a viral pathogen commonly detected in children and immune-compromised populations (elderly, asthmatics), yet more recently was recognized as an important viral pathogen in young adults. Our study evaluated the exacerbation of RSV-associated illness in mice that chronically consumed alcohol for 6 weeks prior to infection...
September 2016: Alcohol
Charles L Francoeur, Stephan A Mayer
For patients who survive the initial bleeding event of a ruptured brain aneurysm, delayed cerebral ischemia (DCI) is one of the most important causes of mortality and poor neurological outcome. New insights in the last decade have led to an important paradigm shift in the understanding of DCI pathogenesis. Large-vessel cerebral vasospasm has been challenged as the sole causal mechanism; new hypotheses now focus on the early brain injury, microcirculatory dysfunction, impaired autoregulation, and spreading depolarization...
October 14, 2016: Critical Care: the Official Journal of the Critical Care Forum
Rosemary O'Connell, Yoichiro Mori
Cortical spreading depression (SD) is a spreading disruption in brain ionic homeostasis during which neurons experience complete and prolonged depolarizations. SD is generally believed to be the physiological substrate of migraine aura and is associated with many other brain pathologies. Here, we perform simulations with a model of SD treating brain tissue as a triphasic continuum of neurons, glia and the extracellular space. A thermodynamically consistent incorporation of the major biophysical effects, including ionic electrodiffusion and osmotic water flow, allows for the computation of important physiological variables including the extracellular voltage (DC) shift...
October 2016: Bulletin of Mathematical Biology
Edgar Santos, Fiorella León, Humberto Silos, Renan Sanchez-Porras, C William Shuttleworth, Andreas Unterberg, Oliver W Sakowitz
The aim was to characterize the effects of magnesium sulfate, using i.v. bolus and local administration, using intrinsic signal imaging, and on electrocorticographic activity during the induction and propagation of spreading depolarizations in the gyrencephalic porcine brain. Local application of magnesium sulfate led to a complete inhibition of spreading depolarizations. One hour after washing out the topical magnesium sulfate, re-incidence of the spreading depolarizations was observed in 50% of the hemispheres...
December 2016: Journal of Cerebral Blood Flow and Metabolism
Michael Johannes Schöll, Edgar Santos, Renan Sanchez-Porras, Modar Kentar, Markus Gramer, Humberto Silos, Zelong Zheng, Yuan Gang, Anthony John Strong, Rudolf Graf, Andreas Unterberg, Oliver W Sakowitz, Hartmut Dickhaus
Haemodynamic responses to spreading depolarizations (SDs) have an important role during the development of secondary brain damage. Characterization of the haemodynamic responses in larger brains, however, is difficult due to movement artefacts. Intrinsic optical signal (IOS) imaging, laser speckle flowmetry (LSF) and electrocorticography were performed in different configurations in three groups of in total 18 swine. SDs were elicited by topical application of KCl or occurred spontaneously after middle cerebral artery occlusion...
September 27, 2016: Journal of Cerebral Blood Flow and Metabolism
Peter Toth, Nikolett Szarka, Eszter Farkas, Erzsebet Ezer, Endre Czeiter, Krisztina Amrein, Zoltan I Ungvari, Jed A Hartings, Andras Buki, Akos Koller
Traumatic brain injury (TBI) is a major health problem worldwide. In addition to its high mortality (35-40%) survivors are left with cognitive, behavioral and communicative disabilities. While little can be done to reverse initial, primary brain damage caused by trauma, the secondary injury of cerebral tissue due to cerebromicrovascular alterations and dysregulation of cerebral blood flow (CBF) is potentially preventable. This review focuses on functional, cellular and molecular changes of autoregulatory function of CBF (with special focus on cerebrovascular myogenic response) that occur in cerebral circulation after TBI and explores the links between autoregulatory dysfunction, impaired myogenic response, microvascular impairment and the development of secondary brain damage...
September 9, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Chunyan Li, Raj K Narayan, Ping Wang, Jed A Hartings
Regional temperature and quantitative regional cerebral blood flow responses to cortical spreading depolarization in the rat were continuously monitored in the same tissue using a microfabricated thermal diffusion sensor that recalibrates and measures in 5-s cycles. The regional cerebral blood flow response had four phases, including early hyperemia (peak: 226% of baseline; duration: 113.1 ± 14.4 s) and late oligemia (minimum: 57%, duration: 28.4 ± 3.7 min). Temperature rose with the start of the regional cerebral blood flow response to a peak increase of 0...
August 31, 2016: Journal of Cerebral Blood Flow and Metabolism
Dan Kaufmann, Jeremy J Theriot, Jekaterina Zyuzin, C Austin Service, Joshua C Chang, Y Tanye Tang, Vladimir B Bogdanov, Sylvie Multon, Jean Schoenen, Y Sungtaek Ju, K C Brennan
Spreading depolarizations are implicated in a diverse set of neurologic diseases. They are unusual forms of nervous system activity in that they propagate very slowly and approximately concentrically, apparently not respecting the anatomic, synaptic, functional, or vascular architecture of the brain. However, there is evidence that spreading depolarizations are not truly concentric, isotropic, or homogeneous, either in space or in time. Here we present evidence from KCl-induced spreading depolarizations, in mouse and rat, in vivo and in vitro, showing the great variability that these depolarizations can exhibit...
August 25, 2016: Journal of Cerebral Blood Flow and Metabolism
Sanjay Kumar Upadhyay, Kartik K Iyer, S Rayaprol, P L Paulose, E V Sampathkumaran
The area of research to discover new Li containing materials and to understand their physical properties has been of constant interest due to applications potential for rechargeable batteries. Here, we present the results of magnetic investigations on a Li compound, Li3Ni2RuO6, which was believed to be a ferrimagnet below 80 K. While our neutron diffraction (ND) and isothermal magnetization (M) data support ferrimagnetism, more detailed magnetic studies establish that this ferrimagnetic phase exhibits some features similar to spin-glasses...
2016: Scientific Reports
Rebecca L Holt, Eric Arehart, Arsen Hunanyan, Nina A Fainberg, Mohamad A Mikati
Several factors, such as epilepsy syndrome, poor compliance, and increased seizure frequency increase the risks of sudden unexpected death in epilepsy (SUDEP). Animal models have revealed that the mechanisms of SUDEP involve initially a primary event, often a seizure of sufficient type and severity, that occurs in a brain, which is vulnerable to SUDEP due to either genetic or antecedent factors. This primary event initiates a cascade of secondary events starting, as some models indicate, with cortical spreading depolarization that propagates to the brainstem where it results in autonomic dysfunction...
May 2016: Seminars in Pediatric Neurology
Dániel Péter Varga, Tamás Puskás, Ákos Menyhárt, Péter Hertelendy, Dániel Zölei-Szénási, Réka Tóth, Orsolya Ivánkovits-Kiss, Ferenc Bari, Eszter Farkas
The significance of prostanoid signaling in neurovascular coupling during somatosensory stimulation is increasingly more appreciated, yet its involvement in mediating the cerebral blood flow (CBF) response to spreading depolarization (SD) has remained inconclusive. Selective cyclooxygenase (COX) enzyme inhibitors (NS-398, SC-560) or an antagonist (L161,982) of the EP4 type prostaglandin E2 receptor were applied topically to a cranial window over the parietal cortex of isoflurane-anesthetized Sprague-Dawley rats (n = 60)...
2016: Scientific Reports
Isabella Ferando, Guido C Faas, Istvan Mody
The synapse specificity of long-term potentiation (LTP) ensures that no interference arises from inputs irrelevant to the memory to be encoded. In hippocampi of aged (21-28 months) mice, LTP was relayed to unstimulated synapses, blemishing its synapse specificity. Diminished levels of the K(+)/Cl(-) cotransporter KCC2 and a depolarizing GABAA receptor-mediated synaptic component following LTP were the most likely causes for the spreading of potentiation, unveiling mechanisms hindering information storage in the aged brain and identifying KCC2 as a potential target for intervention...
September 2016: Nature Neuroscience
Kazutaka Sugimoto, Satoshi Shirao, Hiroyasu Koizumi, Takao Inoue, Fumiaki Oka, Yuichi Maruta, Eiichi Suehiro, Hirokazu Sadahiro, Takayuki Oku, Hiroshi Yoneda, Hideyuki Ishihara, Sadahiro Nomura, Michiyasu Suzuki
Delayed cerebral ischemia (DCI) is a prominent complication after aneurysmal subarachnoid hemorrhage (aSAH). Although vasospasm of proximal cerebral arteries has been regarded as the main cause of DCI, vasospasm of distal arteries, microthrombosis, impaired autoregulation, cortical spreading depolarization (CSD), and spreading ischemia are thought to be involved in DCI after aSAH. Here, we describe a patient with aSAH in whom CSD and cerebrovascular autoregulation were evaluated using simultaneous electrocorticography and monitoring of the pressure reactivity index (PRx) after surgical clipping of a ruptured posterior communicating artery aneurysm...
October 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Lihua Wang, Suzie Dufour, Taufik A Valiante, Peter L Carlen
Seizure activity leads to increases in extracellular potassium concentration ([K[Formula: see text]]o), which can result in changes in neuronal passive and active membrane properties as well as in population activities. In this study, we examined how extracellular potassium modulates seizure activities using an acute 4-AP induced seizure model in the neocortex, both in vivo and in vitro. Moderately elevated [K[Formula: see text]]o up to 9[Formula: see text]mM prolonged seizure durations and shortened interictal intervals as well as depolarized the neuronal resting membrane potential (RMP)...
December 2016: International Journal of Neural Systems
Gemma Huguet, Anoushka Joglekar, Leopold Matamba Messi, Richard Buckalew, Sarah Wong, David Terman
A detailed biophysical model for a neuron/astrocyte network is developed to explore mechanisms responsible for the initiation and propagation of cortical spreading depolarizations and the role of astrocytes in maintaining ion homeostasis, thereby preventing these pathological waves. Simulations of the model illustrate how properties of spreading depolarizations, such as wave speed and duration of depolarization, depend on several factors, including the neuron and astrocyte Na(+)-K(+) ATPase pump strengths. In particular, we consider the neuroprotective role of astrocyte gap junction coupling...
July 26, 2016: Biophysical Journal
Fumiaki Oka, Ulrike Hoffmann, Jeong Hyun Lee, Hwa Kyoung Shin, David Y Chung, Izumi Yuzawa, Shih-Pin Chen, Yahya B Atalay, Ala Nozari, Kristen Park Hopson, Tao Qin, Cenk Ayata
Spontaneous spreading depolarizations are frequent after various forms of human brain injury such as ischemic or hemorrhagic stroke and trauma, and worsen the outcome. We have recently shown that supply-demand mismatch transients trigger spreading depolarizations in ischemic stroke. Here, we examined the mechanisms triggering recurrent spreading depolarization events for many days after subarachnoid hemorrhage. Despite large volumes of subarachnoid hemorrhage induced by cisternal injection of fresh arterial blood in rodents, electrophysiological recordings did not detect a single spreading depolarization for up to 72 h after subarachnoid hemorrhage...
July 18, 2016: Journal of Cerebral Blood Flow and Metabolism
Zoya J R Bastany, Shahbaz Askari, Guy A Dumont, Erwin-Josef Speckmann, Ali Gorji
Spreading depression (SD), a slow propagating depolarization wave, plays an important role in pathophysiology of different neurological disorders. Yet, research into SD-related disorders has been hampered by the lack of non-invasive recording techniques of SD. Here we compared the manifestations of SD in continuous non-invasive electroencephalogram (EEG) recordings to invasive electrocorticographic (ECoG) recordings in order to obtain further insights into generator structures and electrogenic mechanisms of surface recording of SD...
October 1, 2016: Neuroscience
Anja I Srienc, Kyle R Biesecker, Angela M Shimoda, Joanna Kur, Eric A Newman
Cortical spreading depolarization is a metabolically costly phenomenon that affects the brain in both health and disease. Following severe stroke, subarachnoid hemorrhage, or traumatic brain injury, cortical spreading depolarization exacerbates tissue damage and enlarges infarct volumes. It is not known, however, whether spreading depolarization also occurs in the retina in vivo. We report now that spreading depolarization episodes are generated in the in vivo rat retina following retinal vessel occlusion produced by photothrombosis...
September 2016: Journal of Cerebral Blood Flow and Metabolism
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