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Table of Content

    15 November 2014, Volume 9 Issue 21 Previous Issue    Next Issue
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    Effects of low level laser treatment on the survival of axotomized retinal ganglion cells in adult Hamsters
    Kwok-Fai So, Mason Chin Pang Leung, Qi Cui
    2014, 9 (21):  1863-1869.  doi: 10.4103/1673-5374.145337
    Abstract ( 330 )   PDF (1409KB) ( 613 )   Save

    Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the first week with a short period of treatment time (5 minutes) in which 65–66% of retinal ganglion cells survived the optic nerve axotomy whereas 45–47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These findings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal ganglion cells.

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    New drug treatments show neuroprotective effects in Alzheimer’s and Parkinson’s diseases
    Christian Hölscher
    2014, 9 (21):  1870-1873.  doi: 10.4103/1673-5374.145342
    Abstract ( 215 )   PDF (150KB) ( 662 )   Save

    Type 2 diabetes is a risk factor for Alzheimer’s disease and Parkinson’s disease. Insulin signaling in the brains of people with Alzheimer’s disease or Parkinson’s disease is impaired. Preclinical studies of growth factors showed impressive neuroprotective effects. In animal models of Alzheimer’s disease and Parkinson’s disease, insulin, glia-derived neurotrophic factor, or analogues of the incretin glucagon-like peptide-1 prevented neurodegenerative processes and improved neuronal and synaptic functionality in Alzheimer’s disease and Parkinson’s disease. On the basis of these promising findings, several clinical trials are ongoing with the first encouraging clinical results published. This gives hope for developing effective treatments for Alzheimer’s disease and Parkinson’s disease that are currently unavailable.

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    Reactive astrocytes promote axonal remodeling and neurological recovery after stroke
    Zhongwu Liu, Hongqi Xin, Michael Chopp
    2014, 9 (21):  1874-1875.  doi: 10.4103/1673-5374.145343
    Abstract ( 230 )   PDF (115KB) ( 623 )   Save
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    Membrane resealing as a promising strategy for early treatment of neurotrauma
    Xiaoming Jin
    2014, 9 (21):  1876-1877.  doi: 10.4103/1673-5374.145475
    Abstract ( 345 )   PDF (109KB) ( 693 )   Save
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    Sigma-1 receptor: a potential new  target for Parkinson’s disease?
    Veronica Francardo
    2014, 9 (21):  1882-1883.  doi: 10.4103/1673-5374.145351
    Abstract ( 217 )   PDF (182KB) ( 616 )   Save
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    Syringaldehyde exerts neuroprotective effect on cerebral ischemia injury in rats through anti-oxidative and anti-apoptotic properties
    Aras Adem Bozkurt, Guven Mustafa, Akman Tarık, Ozkan Adile, Sen Halil Murat, Kılıcoglu Mesut, Kalkan Yıldıray, Silan Coskun, Cosar Murat
    2014, 9 (21):  1884-1890.  doi: 10.4103/1673-5374.145353
    Abstract ( 168 )   PDF (2637KB) ( 554 )   Save

    There are few studies on the neuroprotective effects of syringaldehyde in a rat model of cerebral ischemia. The study aimed to elucidate the mechanisms underlying the neuroprotective effects of syringaldehyde on ischemic brain cells. Rat models of cerebral ischemia were intraperitoneally administered syringaldehyde. At 6 and 24 hours after syringaldehyde administration, cell damage in the brain of cerebral ischemia rats was obviously reduced, superoxide dismutase activity and nuclear respiratory factor 1 expression in the brain tissue were markedly increased, malondiadehyde level was obviously decreased, apoptosis-related cysteine peptidase caspase-3 and -9 immunoreactivity was obviously decreased, and neurological function was markedly improved. These findings suggest that syringaldehyde exerts neuroprotective effects on cerebral ischemia injury through anti-oxidation and anti-apoptosis.

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    Does progesterone show neuroprotective effects on traumatic brain injury through increasing phosphorylation of Akt in the hippocampus?
    Richard Justin Garling, Lora Talley Watts, Shane Sprague, Lauren Fletcher, David F. Jimenez, Murat Digicaylioglu
    2014, 9 (21):  1891-1896.  doi: 10.4103/1673-5374.145355
    Abstract ( 217 )   PDF (2475KB) ( 487 )   Save

    There are currently no federally approved neuroprotective agents to treat traumatic brain injury. Progesterone, a hydrophobic steroid hormone, has been shown in recent studies to exhibit neuroprotective effects in controlled cortical impact rat models. Akt is a protein kinase known to play a role in cell signaling pathways that reduce edema, inflammation, apoptosis, and promote cell growth in the brain. This study aims to determine if progesterone modulates the phosphorylation of Akt via its threonine 308 phosphorylation site. Phosphorylation at the threonine 308 site is one of several sites responsible for activating Akt and enabling the protein kinase to carry out its neuroprotective effects. To assess the effects of progesterone on Akt phosphorylation, C57BL/6 mice were treated with progesterone (8 mg/kg) at 1 (intraperitonally), 6, 24, and 48 hours (subcutaneously) post closed-skull traumatic brain injury. The hippocampus was harvested at 72 hours post injury and prepared for western blot analysis. Traumatic brain injury caused a significant decrease in Akt phosphorylation compared to sham operation. However, mice treated with progesterone following traumatic brain injury had an increase in phosphorylation of Akt compared to traumatic brain injury vehicle. Our findings suggest that progesterone is a viable treatment option for activating neuroprotective pathways after traumatic brain injury.

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    Effects of diazepam on glutamatergic synaptic transmission in the hippocampal CA1 area of rats with traumatic brain injury
    Lei Cao, Xiaohua Bie, Su Huo, Jubao Du, Lin Liu, Weiqun Song
    2014, 9 (21):  1897-1901.  doi: 10.4103/1673-5374.145357
    Abstract ( 191 )   PDF (606KB) ( 773 )   Save

    The activity of the Schaffer collaterals of hippocampal CA3 neurons and hippocampal CA1 neurons has been shown to increase after fluid percussion injury. Diazepam can inhibit the hyperexcitability of rat hippocampal neurons after injury, but the mechanism by which it affects excitatory synaptic transmission remains poorly understood. Our results showed that diazepam treatment significantly increased the slope of input-output curves in rat neurons after fluid percussion injury. Diazepam significantly decreased the numbers of spikes evoked by super stimuli in the presence of 15 µmol/L bicuculline, indicating the existence of inhibitory pathways in the injured rat hippocampus. Diazepam effectively increased the paired-pulse facilitation ratio in the hippocampal CA1 region following fluid percussion injury, reduced miniature excitatory postsynaptic potentials, decreased action-potential-dependent glutamine release, and reversed spontaneous glutamine release. These data suggest that diazepam could decrease the fluid percussion injury-induced enhancement of excitatory synaptic transmission in the rat hippocampal CA1 area.

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    The occurrence of diffuse axonal injury in the brain: associated with the accumulation and clearance of myelin debris
    Liang Wen, Jun Xu, Tianxiang Zhan, Hao Wang, Xin Huang, Wenchao Liu, Xiaofeng Yang, Renya Zhan
    2014, 9 (21):  1902-1906.  doi: 10.4103/1673-5374.145358
    Abstract ( 308 )   PDF (1095KB) ( 657 )   Save

    The accumulation of myelin debris may be a major contributor to the inflammatory response after diffuse axonal injury. In this study, we examined the accumulation and clearance of myelin debris in a rat model of diffuse axonal injury. Oil Red O staining was performed on sections from the cerebral cortex, hippocampus and brain stem to identify the myelin debris. Seven days after diffuse axonal injury, many Oil Red O-stained particles were observed in the cerebral cortex, hippocampus and brain stem. In the cerebral cortex and hippocampus, the amount of myelin debris peaked at 14 days after injury, and decreased significantly at 28 days. In the brain stem, the amount of myelin debris peaked at 7 days after injury, and decreased significantly at 14 and 28 days. In the cortex and hippocampus, some myelin debris could still be observed at 28 days after diffuse axonal injury. Our findings suggest that myelin debris may persist in the rat central nervous system after diffuse axonal injury, which would hinder recovery.

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    Adult neurogenesis in the four-striped mice (Rhabdomys pumilio)
    Olatunbosun O. Olaleye, Amadi O. Ihunwo
    2014, 9 (21):  1907-1911.  doi: 10.4103/1673-5374.143435
    Abstract ( 224 )   PDF (828KB) ( 777 )   Save

    In this study, we investigated non-captive four-striped mice (Rhabdomys pumilio) for evidence that adult neurogenesis occurs in the adult brain of animal models in natural environment. Ki-67 (a marker for cell proliferation) and doublecortin (a marker for immature neurons) immunostaining confirmed that adult neurogenesis occurs in the active sites of subventricular zone of the lateral ventricle with the migratory stream to the olfactory bulb, and the subgranular zone of the dentate gyrus of the hippocampus. No Ki-67 proliferating cells were observed in the striatum substantia nigra, amygdala, cerebral cortex or dorsal vagal complex. Doublecortin-immunoreactive cells were observed in the striatum, third ventricle, cerebral cortex, amygdala, olfactory bulb and along the rostral migratory stream but absent in the substantia nigra and dorsal vagal complex. The potential neurogenic sites in the four-striped mouse species could invariably lead to increased neural plasticity.

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    Reversible lesions in the brain parenchyma in Wilson’s disease confirmed by magnetic resonance imaging: earlier administration of chelating therapy can reduce the damage to the brain
    Duško B. Kozić, Igor Petrović, Marina Svetel, Tatjana Pekmezović, Aleksandar Ragaji, Vladimir S. Kostić
    2014, 9 (21):  1912-1916.  doi: 10.4103/1673-5374.145360
    Abstract ( 243 )   PDF (371KB) ( 1015 )   Save

    The aim of this study was to evaluate the resolution of brain lesions in patients with Wilson’s disease during the long-term chelating therapy using magnetic resonance imaging and a possible significance of the time latency between the initial symptoms of the disease and the introduction of this therapy. Initial magnetic resonance examination was performed in 37 patients with proven neurological form of Wilson’s disease with cerebellar, parkinsonian and dystonic presentation. Magnetic resonance reexamination was done 5.7 ± 1.3 years later in 14 patients. Patients were divided into: group A, where chelating therapy was initiated < 24 months from the first symptoms and group B, where the therapy started ≥ 24 months after the initial symptoms. Symmetry of the lesions was seen in 100% of patients. There was a significant difference between groups A and B regarding complete resolution of brain stem and putaminal lesions (P = 0.005 and P = 0.024, respectively). If the correct diagnosis and adequate treatment are not established less than 24 months after onset of the symptoms, irreversible lesions in the brain parenchyma could be expected. Signal abnormalities on magnetic resonance imaging might therefore, at least in the early stages, represent reversible myelinolisis or cytotoxic edema associated with copper toxicity.

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    Inhibition of Sirtuin 2 exerts neuroprotection in aging rats with increased neonatal iron intake
    Xijin Wang, Meihua Wang, Liu Yang, Jie Bai, Zhiqiang Yan, Yuhong Zhang, Zhenguo Liu
    2014, 9 (21):  1917-1922.  doi: 10.4103/1673-5374.145361
    Abstract ( 201 )   PDF (557KB) ( 686 )   Save

    Impaired iron homeostasis may cause damage to dopaminergic neurons and is critically involved in the pathogenesis of Parkinson’s disease. At present, very little is understood about the effect of neonatal iron intake on behavior in aging animals. Therefore, we hypothesized that increased neonatal iron intake would result in significant behavior abnormalities and striatal dopamine depletion during aging, and Sirtuin 2 contributes to the age-related neurotoxicity. In the present study, we observed that neonatal iron intake (120 µg/g per day) during postnatal days 10–17 resulted in significant behavior abnormalities and striatal dopamine depletion in aging rats. Furthermore, after AK-7 (a selective Sirtuin 2 inhibitor) was injected into the substantia nigra at postnatal 540 days and 570 days (5 µg/side per day), striatal dopamine depletion was significantly diminished and behavior abnormality was improved in aging rats with neonatal iron intake. Experimental findings suggest that increased neonatal iron intake may result in Parkinson’s disease-like neurochemical and behavioral deficits with aging, and inhibition of Sirtuin 2 expression may be a neuroprotective measure in Parkinson’s disease.

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    Amyloid precursor-like protein 2 C-terminal fragments upregulate S100A9 gene and protein expression in BV2 cells
    Guangzhe Li, Hui Chen, Lin Cheng, Rongjie Zhao, Junchang Zhao, Yanji Xu
    2014, 9 (21):  1923-1928.  doi: 10.4103/1673-5374.145362
    Abstract ( 253 )   PDF (1032KB) ( 853 )   Save

    The murine microglial cell line BV2 has neuroprotective effects, but is toxic to neurons by secreting inflammatory cytokines, and is an important target in the treatment of nerve inflammation and neurodegenerative diseases. In the present study, we observed the effects of transfecting three amyloid precursor-like protein 2 (APLP2) C-terminal fragments (CTFs; C57, C50 and C31) in the pEGFP-N1 vector on S100A9 expression in BV2 cells. Reverse transcription-PCR, western blot assay and immunocytochemistry revealed that S100A9 protein and mRNA expression was greater in BV2 cells after CTF transfection than after mock transfection with an empty vector. Furthermore, transfection of full-length APLP2-751 resulted in low levels of S100A9 protein expression. Our results show that APLP2-CTFs upregulate S100A9 protein and mRNA expression in BV2 cells, and identify a novel pathway involved in neuronal injury and apoptosis, and repair and protection in Alzheimer’s disease.

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    Hot spots and future directions of research on the neuroprotective effects of nimodipine
    Runhui Li
    2014, 9 (21):  1933-1938.  doi: 10.4103/1673-5374.145365
    Abstract ( 219 )   PDF (856KB) ( 1454 )   Save

    Calcium antagonists are widely used in the clinical treatment of ischemic cerebrovascular disease because of their vascular and neuroprotective effects. Nimodipine, a typical calcium antagonist, can cross the blood-brain barrier and act selectively at neurons and blood vessels of target tissues, thus exerting neuroprotective effects. The aim of the present study was to explore the hot spots and future trends of research on the neuroprotective effects of nimodipine. We retrieved 425 articles on the neuroprotective effects of nimodipine that were indexed in the Web of the Science database between 2000 and 2014. The retrieved articles were analyzed using document analysis reporting and the derived information function in the Web of Science, and the information visualization software CiteSpace III. The reference co-citation network was plotted, and the high frequency key words in these publications were used to analyze the research fronts and development trends for nimodipine neuroprotection. According to these co-citation clusters, the research front of nimodipine neuroprotection is the use of randomized controlled trials to study nimodipine intervention of subarachnoid hemorrhage. Using time zone view analysis on hot spots labeled with a key word, the areas of interest in the field of nimodipine neuroprotection are nimodipine pharmacology and therapeutics, blood-brain barrier, trials, and anti-angiospasm.

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