Neuroscience
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In Parkinson's disease (PD), elevated beta (15-35Hz) power in subcortical motor networks is widely believed to promote aspects of PD symptomatology, moreover, a reduction in beta power and coherence accompanies symptomatic improvement following effective treatment with l-DOPA. Previous studies have reported symptomatic improvements that correlate with changes in cortical network activity following GABAA receptor modulation. In this study we have used whole-head magnetoencephalography to characterize neuronal network activity, at rest and during visually cued finger abductions, in unilaterally symptomatic PD and age-matched control participants. ⋯ However, the absolute level of movement-related beta desynchronization was not altered. These results show that low-dose zolpidem not only reduces contralateral beta but also increases ipsilateral beta, while rebalancing the dynamic range of M1 network oscillations between the two hemispheres. These changes appear to underlie the symptomatic improvements afforded by low-dose zolpidem.
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Empathy for pain, a widely studied sub-form of empathy, is an ability to recognize and share the pain of others. It involves brain regions associated with the emotional component of pain. Recent studies found that emotional pain could be modulated by stimulating the dorsolateral prefrontal cortex (DLPFC) with transcranial direct current stimulation (tDCS). ⋯ It was found that ratings for others' pain increased in subjects with an anodal tDCS of the DLPFC in comparison to those with sham tDCS, indicating enhanced pain empathy with the anodal tDCS. Furthermore, the changes of ratings for others' pain were positively correlated with the changes of pain-related self-unpleasantness. These findings indicate that tDCS could modulate pain empathy and be used as a potential tool for modulating diseases accompanied with empathy deficits.
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Hippocampal neurons must maintain control over cytosolic calcium levels, especially during development, as excitation and calcium flux are necessary for proper growth and function. But excessive calcium can lead to excitotoxic cell death. Previous work suggests that neonatal male and female hippocampal neurons regulate cytosolic calcium differently, thereby leading to differential susceptibility to excitotoxic damage. ⋯ Surprisingly, there was no sex difference in the level of any of the three proteins. Treatment with DHT significantly decreased PMCA1 and NCX1, but increased SERCA2 protein levels in very young animals but not at a later timepoint. Taken together, these data suggest a complex interaction of sex, hormones, calcium regulation and developmental age; however androgens acting during the first week of life are implicated in regulation of hippocampal cell death and may be an underlying mechanism for sexually dimorphic apoptosis.
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Withdrawal from amphetamine is associated with increased anxiety and sensitivity to stressors which are thought to contribute to relapse. Rats undergoing amphetamine withdrawal fail to exhibit stress-induced increases in serotonin (5-HT) release in the ventral hippocampus and show heightened anxiety-like behaviors. Therefore, we tested the hypothesis that reducing 5-HT levels in the ventral hippocampus is a causal mechanism in increasing anxiety-like behaviors during amphetamine withdrawal. ⋯ This effect was reversed by ventral hippocampus infusion of paroxetine. Our results suggest that 5-HT levels in the ventral hippocampus are critical for regulating anxiety behavior. Increasing 5-HT levels during withdrawal may be an effective strategy for reducing anxiety-induced drug relapse.
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To identify molecular candidates involved in brain disabilities of Ts1Cje, a mouse model of Down syndrome (DS), we performed comparative proteomic analyses. Proteins extracted from the brains of postnatal wild-type (WT) and Ts1Cje mice were analyzed by two-dimensional gel electrophoresis (2-DE). No differences were detected in the proteins expressed in the whole brain between WT and Ts1Cje mice at postnatal day 0 and 3months of age. ⋯ CACYBP and NDPK-B were involved in cell proliferation, whereas TK and PK were associated with energy metabolism. Experiments on cell proliferation, an in vivo bromodeoxyuridine (BrdU)-labeling experiment, and immunohistochemical analysis for phospho-histone H3 (an M-phase marker) demonstrated increased numbers of BrdU-positive and M-phase cells in the ganglionic eminence. Our findings suggest that the dysregulated expression of proteins demonstrated by comparative proteomic analysis could be a factor in increased cell proliferation, which may be associated with abnormalities in DS brain during embryonic life.