Neuroscience
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Parkinson's disease (PD) is a prevalent age-related neurodegenerative disorder that results in the progressive impairment of motor and cognitive functions. The majority of PD cases are sporadic, and only 5% of patients are associated with mutations in a few genes, which cause the early onset or familial PD. ⋯ In the last decade, genomic and proteomic studies have shown an increasing molecular complexity of sporadic PD, suggesting that a broad spectrum of biochemical pathways underlie its progression. Recent investigations and the literature review suggest the potential role of deregulation of the sensitive-cysteine proteome as a convergent pathogenic mechanism that may contribute to this complexity, opening new therapeutic opportunities.
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Affective temperaments and childhood-trauma experiences are associated with major depressive disorder (MDD). So far, how the covariation between distinct affective temperaments and childhood-trauma insulted brain functional connectivities (FCs) contribute to MDD remains unclear. Here, we aimed to investigate whether certain brain FC patterns are related to certain affective temperaments and whether the FCs contribute to depressive symptom dimensions of MDD patients. ⋯ Moreover, the covariation between the PLS FC profile and the PLS affective-temperament profile were enhanced in the MDD patients compared to healthy controls. In MDD participants alone, the affective-temperament modulated FC profile (mainly of the lingual and temporal cortex) was associated with the somatization symptom dimension when age, sex, ill-duration, age-of-onset, and HARS scores were adjusted. The findings imply possible neural correlates of affective temperaments and may find applications in intervention of the somatization-depression symptoms by stimulation of the related neural correlates.
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Observers typically present a strong bias in estimating the orientation of a visual bar when their body is tilted >60° in the roll plane and in the absence of visual background information. Known as the A-effect, this phenomenon likely results from the under-compensation of body tilt. Static visual cues can reduce such bias in the perceived vertical. ⋯ This result was present in the tilted but not in the upright participants. In the interception task, the timing error increased linearly as a function of the orientation of the parabola. These results support the hypothesis that a gravity vector estimated from dynamic visual stimuli contributes to the subjective visual vertical.
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The p75 neurotrophin receptor (p75NTR) is a multifunctional protein that regulates cellular responses to pathological conditions in specific regions of the nervous system. Activation of p75NTR in certain neuronal populations induces proteolytic processing of the receptor, thereby generating p75NTR fragments that facilitate downstream signaling. Expression of p75NTR has been reported in neurons of the ventral midbrain, but p75NTR signaling mechanisms in such cells are poorly understood. ⋯ Furthermore, inhibition of c-Jun N-terminal Kinase (JNK) decreased p75NTR cleavage induced by oxidative damage. Altogether, these results support a mechanism of p75NTR activation in which oxidative stress stimulates JNK signaling, thereby facilitating p75NTR processing via a ligand-independent mechanism involving induction of metalloprotease and γ-secretase activity. These findings reveal a novel role for JNK in ligand-independent p75NTR signaling, and, considering the susceptibility of mesencephalic neurons to oxidative damage associated with Parkinson's disease (PD), merit further investigation into the effects of p75NTR on PD-related neurodegeneration.
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Functional connectivity in EEG resting-state is not stable but fluctuates considerably. The aim of this study was to investigate how efficient information flows through a network, i.e. how resting-state EEG networks are organized and whether this organization it also subject to fluctuations. Differences of the network organization (small-worldness), degree of clustered connectivity, and path length as an indicator of how information is integrated into the network across time was compared between theta, alpha and beta bands. ⋯ It is therefore the interplay of local processing efficiency and global information processing efficiency in the brain that fluctuates in a frequency-specific way. Properties of how information can be integrated is subject to fluctuations in a frequency-specific way in the resting-state. The possible relevance of these resting-state EEG properties is discussed including its clinical relevance.