Journal of molecular neuroscience : MN
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A growing body of evidence suggests the existence of a functional interaction between gabapentin (GBP)-morphine system. However, the neuro-anatomical sites and molecular mechanism of action of gabapentin-morphine interaction to prevent and reverse morphine side effects as well as enhancement of the analgesic effect of morphine is not clear. Therefore, we examined the combined effects of GBP-morphine on acute morphine-induced c-Fos expression in rat nucleus accumbens. ⋯ The present study demonstrated that, administration of GBP (150 mg/kg, i.p.) in combination with morphine (5 mg/kg, i.p.) significantly (p < 0.01) attenuated the acute morphine (5 mg/kg, i.p.)-induced c-Fos expression in the rat nucleus accumbens shell. Present results showed that GBP-morphine combination action prevented the acute morphine-induced c-Fos expression in rat nucleus accumbens. Moreover, this study provides first evidence of neuro-anatomical site and that GBP neutralized the morphine-induced activation of rat nucleus accumbens shell.
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The relationship between β-amyloid (Aβ) and tau is not fully understood, though it is proposed that in the pathogenesis of Alzheimer's disease (AD) Aβ accumulation precedes and promotes tau hyperphosphorylation via activation of glycogen synthase kinase-3beta (GSK-3β). Both events contribute to learning and memory impairments. Modulation of γ-secretase activity has proved to reduce the Aβ burden and cognitive deficits in mouse models of AD, but its ability in reducing the tau pathology remains elusive. ⋯ CHF5074 was more effective than ibuprofen in reducing tau pathology, though both compounds decreased the GSK-3β level and increased the GSK-3β inhibitory phosphorylation near to the non-Tg values. The inhibition of GSK-3β appeared to be secondary to the reduction of Aβ generation as, differently from LiCl, CHF5074 reproduced its effect in hAPP-overexpressing neuroglioma cells, but not in wild-type primary neurons. Our data show that the novel γ-secretase modulator CHF5074 can fully reverse β-amyloid-associated tau pathology, thus representing a promising therapeutic agent for AD.
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The prediction of outcome after ischemic stroke (IS) is currently based on indirect data from clinical and radiological evaluation. We evaluated the usefulness of serum Tau protein as possible prognostic markers for IS. Fifty-six patients with computed tomography-confirmed IS were enrolled. ⋯ Patients in whom Tau protein was detected in serum, when compared with patients without Tau protein, developed more severe neurological deficits, had worse functional status measured in the early and late phase of IS, and were found to have larger volume of infarction. However, Tau protein concentrations measured within the early phase of IS did not correlate with degrees of neurological deficit and disability in the early phase and also after 3 months of IS. Detection of Tau protein in the serum of patients with IS but not its concentration can be considered as a bad prognostic factor for the clinical outcome in early and late phase of IS.
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Anxiety disorders are frequently long-lasting and debilitating for more than 40 million American adults. Although stressor exposure plays an important role in the etiology of some anxiety disorders, the mechanisms by which exposure to stressful stimuli alters central circuits that mediate anxiety-like emotional behavior are still unknown. Substantial evidence has implicated regions of the central extended amygdala, including the bed nucleus of the stria terminalis (BNST) and the central nucleus of the amygdala as critical structures mediating fear- and anxiety-like behavior in both humans and animals. ⋯ Psychoneuroendocrinology 34:833-843, 2009). We describe how interactions between PACAP and CRH in the BNST may mediate stress-associated behaviors, including anorexia and anxiety-like behavior. These studies have the potential to define specific mechanisms underlying anxiety disorders, and may provide important therapeutic strategies for stress and anxiety management.
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The hyperexcitability of trigeminal ganglion (TG) neurons following inflammation or C-fiber stimulation is known to be involved in a variety of changes in gene expression in TG neurons, resulting in pain abnormalities in orofacial regions. We analyzed nocifensive behavior following complete Freund's adjuvant (CFA) or capsaicin injection into the maxillary whisker pad, and gene expression in the TG neurons using microarray analysis. The head-withdrawal latency to capsaicin injection or the head-withdrawal threshold to mechanical stimulation of the whisker pad skin in CFA-treated rats was significantly decreased compared to vehicle-treated rats. ⋯ Genes which have not been linked to peripheral inflammation or C-fiber activation were detected. Moreover, microarray chip containing a number of non-coding sequences was also up-regulated by C-fiber activation. These findings suggest that the diverse gene expressions in TG neurons are differentially involved in the inflammatory chronic pain and the acute pain induced by C-fiber activation, and the hyperexcitation of C-fibers are associated with the activation of certain non-coding RNAs.