Neuroscience letters
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Neuroscience letters · Oct 2013
Immunohistochemical demonstration of urocortin 1 in Edinger-Westphal nucleus of the human neonate: colocalization with tyrosine hydroxylase under acute perinatal hypoxia.
Perinatal hypoxia could cause long-term disturbances of the dopaminergic (DA) systems, leading to behavioral and/or neurological deficits later in life. Increased expression of tyrosine hydroxylase (TH) was shown in the substantia nigra (SN) and ventral tegmental area (VTA) of human neonates that suffered severe/acute perinatal hypoxic insults, but also in all neurons of the Edinger-Westphal nucleus (EW). Since EW, in humans, contains urocortin 1 (UCN1)/centrally projecting neurons (EWcp), we investigated: (a) the development of UCN1-positive neurons and the possible effect of neonatal hypoxic/ischemic encephalopathy on UCN1 expression and (b) the possible colocalization of UCN1 with TH in neonates with histological signs of acute hypoxic injury. ⋯ In EWcp, a positive correlation was found between UCN1 expression and the age of the neonates, but not with hypoxia neuropathological grade. UCN1 was colocalized with TH in most EWcp neurons. Since UCN1 in EWcp may play a significant role in stress adaptation and consequently in stress-related disorders, the role of catecholamine synthesis in this nucleus under acute hypoxic conditions must be further investigated.
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Neuroscience letters · Oct 2013
Modulation of thermal somatosensory thresholds within local and remote spinal dermatomes following cervical repetitive magnetic stimulation.
Repetitive magnetic stimulation (rMS) modulates thermal somatosensory function at both low (0.2-1.0Hz) and high (5.0-20.0Hz) frequencies within the conditioned dermatome. However the effects of 1Hz and 20Hz cervical (C6-C7) rMS on thermosensory thresholds and contact heat evoked potentials (CHEPs) tested within local and remote spinal dermatomes are not known. ⋯ Both 1 and 20Hz cervical rMS modulated warm detection threshold within the locally conditioned C6 dermatome. The concomitant increase in warm detection threshold within the T10 dermatome following 1Hz rMS provides evidence for remote neuromodulation of thermosensory function via intraspinal control mechanisms.
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Neuroscience letters · Oct 2013
Regional cerebral blood flow alterations in obstructive sleep apnea.
Obstructive sleep apnea (OSA) is a condition characterized by upper airway muscle atonia with continued diaphragmatic efforts, resulting in repeated airway obstructions, periods of intermittent hypoxia, large thoracic pressure changes, and substantial shifts in arterial pressure with breathing cessation and resumption. The hypoxic exposure and hemodynamic changes likely induce the structural and functional deficits found in multiple brain areas, as shown by magnetic resonance imaging (MRI) procedures. Altered cerebral blood flow (CBF) may contribute to these localized deficits; thus, we examined regional CBF, using arterial spin labeling procedures, in 11 OSA (age, 49.1±12.2 years; 7 male) and 16 control subjects (42.3±10.2 years; 6 male) with a 3.0-Tesla MRI scanner. ⋯ Lateralized, decreased CBF appeared near the left inferior cerebellar peduncles, left tapetum, left dorsal fornix/stria terminalis, right medial lemniscus, right red nucleus, right midbrain, and midline pons. Regional CBF values in OSA are significantly reduced in major sensory and motor fiber systems and motor regulatory sites, especially in structures mediating motor coordination; those reductions are often lateralized. The asymmetric CBF declines in motor regulatory areas may contribute to loss of coordination between upper airway and diaphragmatic musculature, and lead to further damage in the syndrome.
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Neuroscience letters · Oct 2013
Mannitol enhances therapeutic effects of intra-arterial transplantation of mesenchymal stem cells into the brain after traumatic brain injury.
Traumatic brain injury (TBI) sustained in a traffic accident or a fall is a major cause of death that affects a broad range of ages. The aim of this study was to investigate the therapeutic effects of intra-arterial transplantation of mesenchymal stem cells (MSCs) combined with hypertonic glycerol (25%) or mannitol (25%) in a TBI model of rats. TBI models were produced with a fluid percussion device. ⋯ Immunohistochemically, more MSCs were observed in the injured brain tissues of mannitol-treated rats than in glycerol or PBS-treated rats at 24h after transplantation. Intra-arterial transplantation of MSCs combined with mannitol is an effective treatment in a TBI model of rats. This technique might be used for patients with diseases of the central nervous system including TBI.
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Neuroscience letters · Oct 2013
Carvacrol alleviates cerebral edema by modulating AQP4 expression after intracerebral hemorrhage in mice.
Carvacrol is a natural compound extracted from many plants of the family Lamiaceae. Previous studies have demonstrated that carvacrol has potential neuroprotective effects in central nervous system diseases such as Alzheimer's disease and cerebral ischemia. In this study, we investigated the preclinical effect of carvacrol on cerebral edema after intracerebral hemorrhage (ICH) using a bacterial collagenase-induced ICH mouse model. ⋯ We also found that carvacrol treatment decreased AQP4 mRNA in a dose-dependent manner at 24h. Furthermore, AQP4 protein expression in the perihematomal area was reduced by carvacrol significantly at day 3 after ICH (p<0.05). Our findings suggest that carvacrol may exert its protective effect on ICH injury by ameliorating AQP4-mediated cerebral edema.