Neuroscience
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Trigeminal neuropathic pain (TGN) is an attacking, abrupt, electric-shock headache involving abnormal cortical activity. The neural mechanism underlying TGN remains elusive. In this study, we explored the role of microglia in the primary somatosensory barrel cortex (S1BF), which is a critical region for TGN, of a mouse model of TGN that displayed significant pain-related behaviors. ⋯ In addition, we found that microglia in the S1BF (microgliaS1BF) were significantly activated, with density and morphology changes. Intraperitoneal administration of minocycline, a microglia inhibitor, attenuated pain sensitization, and decreased GluS1BF neuronal activity. Together, these findings demonstrate the putative importance of microglia as a key regulator in TGN through actions on GluS1BF neuronal adaptation.
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Varicella zoster virus (VZV) results in chicken pox and herpes zoster. Female rats show a higher level of herpes zoster associated pain than males, consistent with human studies. In this study, we addressed the novel hypothesis that sex difference in herpes zoster associated pain is due, in part, to estradiol modulating activity in the thalamus. ⋯ Our results show that a high dose of estradiol significantly reduced the pain response in both males and females. pERK significantly increased in excitatory cells after treatment with a low dose of estradiol and increased in inhibitory cells after treatment with a high dose of estradiol. Administration of ICI 182,780 significantly increased the pain response, reduced expression of GABA related genes in the thalamic region and significantly reduced the number of inhibitory cells expressing pERK. The results suggest that estradiol attenuates herpes zoster pain by increasing the activity of inhibitory neurons within the thalamus and that this reduction includes an estrogen receptor dependent mechanism.
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Computer-aided diagnosis has become a widely-used auxiliary tool for the diagnosis of Alzheimer's disease (AD). In this study, we developed an extreme learning machine (ELM) model to discriminate between patients with AD and normal controls (NCs) using voxel-based morphometry (VBM) obtained from magnetic resonance imaging. Support vector machine (SVM), Gaussian process regression (GPR), and partial least squares (PLS) regression were compared with the ELM model. ⋯ We applied the proposed methods to data from 58 patients with AD and 94 NCs, and achieved a classification accuracy of up to 0.96 with all classification features of the ELM model, while the results of the other three models were 0.82 (PLS), 0.79 (GPR), and 0.75 (SVM). Furthermore, the effect of VBM parameter modeling is better than texture parameter. Thus, our method was optimal in distinguishing patients with AD from NCs, and may therefore be useful for the diagnosis of AD.
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Embryonic light exposure affects similarly functional lateralization in fish and birds. While the light acts on an asymmetric habenular system during the first post fertilization hours in zebrafish, in the domestic chicks it shapes the thalamofugal visual pathway affecting the right retinal photoreceptors in the last stages before hatching. However, recent evidence has shown that also in chicks a precocial embryonic time window seems open to light action. ⋯ The perseveration of pecks directed to irrelevant elements revealed that in all chicks the right hemisphere was heavily attracted by the novel elements when tested with the left eye. When using the right eye, instead, only DK chicks attended repeatedly to distractors whereas LL and EL chicks showed a left hemisphere advantage for fine discrimination and sustained attention; conversely, when tested binocularly, LL chicks perseverated significantly more than both DK and EL chicks, likely compensating the distraction with the analysis carried out by both hemispheres. For the first time, we unveiled a fine graded difference between the light modulation exerted during the two time windows, adding evidence to the idea that genes and environmental factors interplay in several separate routes to the modulation of the neurodevelopment of cerebral lateralization in vertebrates.
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An important prerequisite for the analysis of spike synchrony in extracellular recordings is the extraction of single-unit activity from the multi-unit signal. To identify single units, potential spikes are separated with respect to their potential neuronal origins ('spike sorting'). However, different sorting algorithms yield inconsistent unit assignments, which seriously influences subsequent spike train analyses. ⋯ If the latter is less important ('clean' data) the K-Means algorithm is a better option. Our results strongly argue for the need of standardized validation procedures based on ground truth data. The recipe suggested here is simple enough to become a standard procedure.