Brain research
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Randomized Controlled Trial
Pain assessment by continuous EEG: association between subjective perception of tonic pain and peak frequency of alpha oscillations during stimulation and at rest.
Recordings of neurophysiological brain responses to noxious stimuli have been traditionally based on short stimuli, in the order of milliseconds, which induce distinct event-related potentials (ERPs). However, using such stimuli in the experimental setting is disadvantageous as they are too brief to faithfully simulate clinical pain. We aimed at utilizing continuous EEG to investigate the properties of peak alpha frequency (PAF) as an objective cortical measure associated with subjective perception of tonic pain. ⋯ These psychophysical-neurophysiological relations attest to the properties of PAF as a novel cortical objective measure of subjective perception of tonic pain. Moreover, resting-state PAFs might hold inherent pain modulation attributes, possibly enabling the prediction of individual responsiveness to prolonged pain. The relevance of PAF to the neural processing of tonic pain may indicate its potential to advance pain research as well as clinical pain characterization.
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Protocadherin-19 has been implicated in some neurological diseases, but even the basic properties of this protocadherin have not yet been characterized well. Hence, various basic properties of chicken protocadherin-19 were examined to elucidate its biological role. The protocadherin-19 expressed in L cells was localized at the intercellular contact sites and showed Ca(2+)-dependent homophilic cell aggregation activity that was relatively weak but showed stringent specificity. ⋯ In the chicken retina, protocadherin-19 was expressed as early as embryonic day 5 and was localized in the ganglion cell layer, inner plexiform layer, and optic nerve layer. Chicken protocadherin-19 was co-localized with syntaxin 1 in inner plexiform layer and was also expressed in the optic nerve and in specific layers of optic tectum. These results suggest that protocadherin-19 plays a role as an adhesion protein in optic nerve fiber bundling, optic nerve targeting, and/or synapse formation.
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Sex differences in structure and organization of the corpus callosum (CC) have been identified in healthy adults and may be linked to distinct functional lateralization and processing in men and women. Magnetic resonance imaging (MRI) has facilitated noninvasive assessment of CC sex differences in morphology by volumetric imaging and microstructural organization by diffusion tensor imaging (DTI). Incorporation of recently developed myelin-water fraction (MWF) imaging may improve our understanding of CC sex differences. ⋯ No significant sex-differences existed for mean diffusivity, axial diffusivity, radial diffusivity or FDi. Correlations between DTI parameters and MWF were significant but weak. Results of this study demonstrate regionally dependent sex differences in microstructural composition and organization of the CC and the lack of correlation between DTI and MWF suggest both measures provide unique information within the CC.
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Transplantation of mesenchymal stem cells (MSCs) derived from bone marrow has been shown to improve functional outcome in spinal cord injury (SCI). Systemic delivery of MSCs results in therapeutic benefits in a number of experimental central nervous system disorders. In the present study we intravenously administered rat MSCs derived from bone marrow at various time points after induction of a severe contusive SCI in rat to study their therapeutic effects. ⋯ Functional outcome measurements using the Basso-Beattie-Bresnehan (BBB) score were performed periodically up to 6 weeks post-SCI. Locomotor recovery improvement was greater in the MSC-treated groups than in sham controls with greatest improvement in the earlier post-contusion infusion times. The availability of autologous MSCs in large number and the potential for systemically delivering cells to target lesion areas without neurosurgical intervention suggests the potential utility of intravenous cell delivery as a prospective therapeutic approach in acute and subacute SCI.
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We have reported the neuroprotective effects of pre-treatment with beta-adrenoceptor antagonists on the cerebral infarction at 1 and 7 days after focal ischemia in rats. However, the protective effect of post-treatment with beta-adrenoceptor antagonists has not been investigated yet. This study was conducted to evaluate the post-treatment effects of selective beta(1)-adrenoceptor antagonists in the rat focal cerebral ischemia. ⋯ Neurological deficit scores were lower in the rats treated with esmolol or landiolol, compared with saline-treated rats at 1 day as well as 4 and 7 days. The infarct volumes of cortical and striatum were less in the rats receiving beta-adrenoceptor antagonists than in saline-treated rats (P<0.05). The current study indicates that administration of selective beta1-adrenoceptor antagonists after the onset of ischemia also improved neurological and histological outcomes following transient focal cerebral ischemia in rats.