Neuroscience
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Defective proprioceptive integration may play a role in the pathophysiology of motor symptoms in Parkinson's disease (PD). Dysfunction related to proprioceptively-evoked postural reactions in PD patients is still a controversial issue, with only a limited number of studies to date and mostly discordant results. The aims of the present study were (1) to determine whether or not the proprioceptive defect in PD underlies postural impairment and (2) whether or not deep brain stimulation of the subthalamic nucleus (STN-DBS) affects proprioceptive integration. ⋯ We found a significant positive effect of STN-DBS on these postural features. Our findings indicate that Parkinson patients, even in the absence of any clinical evidence of instability, falls, or freezing, use proprioceptive information for postural control less efficiently than healthy subjects. Furthermore, STN-DBS was found to improve proprioceptive integration, with positive impacts on postural orientation and balance.
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The anterior cingulate cortex (ACC) is vulnerable to stress. Its dysfunction is observed in psychiatric disorders manifested as alterations in network oscillations. Mechanisms linking stress load to disturbed emotional-cognitive behaviors are of essential importance to further elucidate therapeutic strategies for psychiatric diseases. ⋯ Noradrenaline increased the PSD of the theta (3-8 Hz) components in both the control and CRS groups, and also in alpha components only in the CRS group. Dopamine did not modulate the PSD of any frequency components in the control mice, whereas it enhanced the PSD of theta and alpha components in CRS mice. It was suggested that chronic stress load affects the dynamics of the network oscillations in the ACC with enhanced cathecolaminergic modulation.
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Long non-coding RNAs (lncRNAs) play critical roles in regulating the progression of cerebral ischemia. LncRNA H19 was significantly up-regulated under ischemia-reperfusion (I/R) damage and implicatedin I/R injury progression, but the mechanisms remain unclear. Mice were subjected to middle cerebral artery occlusion (MCAO)/R (1 h/24 h) to build an I/R injury model and the infarct volume and neurological deficit were assessed. ⋯ H19 knockdown and miR-19a-3p overexpression relieved I/R or OGD/R induced neuronal cell oxidative stress and apoptosis. H19/miR-19a-3p/PTEN axis could promote cerebral I/R injury via PI3K/AKT pathway. These demonstrated a mechanism how H19 participates in I/R injury, and provided us a potential target for I/R injury diagnosis and treatment.
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The day-active tree shrew may serve as an animal model of human-like diurnal rhythms. However, the molecular basis for circadian rhythms in this species has remained unclear. In the present study, we investigated the expression patterns of core circadian genes involved in transcriptional/translational feedback loops (TTFLs) in both central and peripheral tissues of the tree shrew. ⋯ Additionally, the peripheral clock was phase-advanced relative to the brain clock, as there was a significant advance (2-4 h) for PER3, DBP, NR1D1 and NR1D2. Furthermore, these genes exhibited an anti-phasic relationship between the diurnal tree shrew and the nocturnal mouse (i.e., 12-h phasing differential). Collectively, our findings demonstrate a characteristic expression pattern of core circadian genes in the tree shrew, which may provide a means for elucidating molecular mechanisms of diurnal rhythms.
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Individuals with mild cognitive impairment (MCI) are regarded as being at high risk of developing Alzheimer's disease (AD). The apolipoprotein E (APOE) ε4 allele is a well-established genetic risk factor for developing AD. In the present study, by using voxel-mirrored homotopic connectivity (VMHC), we aimed to explore the potential functional disruptions in MCI APOE-ε4 carriers. ⋯ The results showed that MCI APOE-ε4 carriers presented increased VMHC in the inferior frontal gyrus/insula and middle frontal gyrus/superior frontal gyrus in comparison with noncarriers. We found that MCI APOE-ε4 carriers showed increased functional connectivity between the seed regions (bilateral inferior frontal gyri/insula and bilateral middle frontal gyri/superior frontal gyri) and broad brain areas, including the frontal, temporal, parietal, and cerebellar regions. Our findings provide neuroimaging evidence for the modulation of the APOE genotype on the neurodegenerative disease phenotype and may be potentially important for monitoring disease progression in double-high-risk populations of AD.