Experimental Brain Research最新文献

Deubiquitinating enzymes of the ubiquitin-specific peptidase (USP) family have been increasingly recognized for their roles in modulating neuropathic pain. In this study, bioinformatic analysis identified USP19 as a downregulated gene in trigeminal neuralgia (TN). Using a mouse model of TN induced by foramen lacerum impingement of the trigeminal nerve (FLIT), we demonstrated that adeno-associated virus-mediated overexpression of USP19 in the cerebral cortex significantly alleviated anxiety-like and pain-like behaviors. USP19 overexpression promoted deubiquitination and stabilization of fused in sarcoma (FUS), as confirmed by Western blotting, actinomycin D treatment, and ubiquitination assays. In HT22 and SH-SY5Y cells exposed to lipopolysaccharide to induce mitochondrial dysfunction, USP19 restored mitochondrial membrane potential, reduced mitochondrial reactive oxygen species, suppressed DRP1 phosphorylation, and upregulated CYTB and ND4 levels. These effects were reversed by FUS knockdown, both in vitro and in vivo. Moreover, FUS silencing abolished USP19-mediated improvements in NAD⁺/NADH ratio and mitochondrial function, as well as its analgesic and anxiolytic benefits in TN mice. These findings suggest that USP19 alleviates TN by enhancing FUS deubiquitination and preserving mitochondrial integrity in neurons. This study reveals a novel USP19/FUS signaling axis in the regulation of mitochondrial homeostasis and provides a promising therapeutic target for the treatment of TN.

This study aims to explore the neural impact of virtual reality (VR) motion sickness on individuals from the perspective of brain functional networks, analyze the relationship between changes in Electroencephalogram (EEG) frequency bands and VR motion sickness, and provide a new perspective for evaluating the neural excitation mechanism of VR motion sickness. Twenty-six subjects were grouped based on their sensitivity to VR by a subjective evaluation scale. EEG signals were recorded before and after VR experiment. Functional brain networks were constructed and the changes in perspective of network topological characteristic parameters were analyzed. Participants in the sensitive group exhibited increased clustering coefficients and local efficiencies in the Delta band, as well as increased characteristic path lengths in the Alpha band. Conversely, subjects in the insensitive group exhibited no substantial alterations in brain network parameters before and after the VR experiment, and no significant changes in other frequency bands. The result indicate that alterations in the Delta and Alpha frequency bands play a crucial role in the mechanism of VR-induced motion sickness. These changes reflect an augmentation of the brain's local information processing capacity in response to VR motion sickness, as well as modifications in the efficiency of the global network in processing visual stimuli and modulating attention. These findings provide theoretical underpinnings for the neurological effects of VR motion sickness and establish a foundational framework for future research.

Mental fatigue is a psychobiological state brought on by long periods of demanding cognitive activity and can impact cognitive performance. The aim of this study was to determine whether mental fatigue affects decision-making performance (response time and accuracy) during a collision avoidance task. Twenty-six young adults were randomly assigned to either a mental fatigue or a control group. In a virtual environment, participants approached a 90 cm doorway while a virtual person approached from the opposite side. As participants reached two meters from the doorway, the screen went blank, and they were instructed to respond as quickly and accurately as possible whether they would pass through the doorway first. The virtual person approached at four different speeds relative to the participant's average walking speed (i.e. 0.8×, 0.9×, 1.1×, and 1.2×). After completing 20 trials, the mental fatigue group completed a 30-minute Stroop task while the control group watched a 30-minute documentary, followed by another block of the crossing order task. A 5-minute psychomotor vigilance task (PVT) was used as a behavioural measure of mental fatigue. Statistical analyses revealed a significant time by group interaction for PVT performance, such that the mental fatigue group demonstrated slower response times following the Stroop task. However, both groups demonstrated significantly faster response times and improved accuracy during the crossing order task following their respective intervention. The findings of this study suggest that the task was not cognitively demanding enough to reveal performance impairments associated with mental fatigue.

The hand grasp of an object is normally consistent, determined by the optimal, most efficient strategy learnt from previous experience. Yet in certain settings, despite object properties remaining constant and intention the same, the grasp chosen by an individual can vary with a lack of clear preference for a particular grasp configuration. This is referred to as motor ambiguity. Here, we compare the influence of preceding static versus dynamic visual information on participants' choice between two possible hand configurations when grasping an object at various orientations. We confirm previous findings that presentation of an object in an initial static orientation prior to the grasping in ambiguous orientation causes subjects to select a grasp that would be most congruent with the initial, determinate orientation. However, we unexpectedly found that when object rotation is observed between the initial and target positions, the bias is inversed, i.e. subjects choose the alternate grasp configurations. Furthermore, the inverse bias strength was found to be independent of the motion magnitude, and persists even when greater decision time is allowed. We discuss several possibilities across perceptual and decision making circuitry that might manifest this behavioural phenomenon.

We address the underexplored role of visual feedback in ensuring stability of pressing force produced in isometric conditions by the two hands. We considered the task as a two-level hierarchy (total force, F_TOT, and hand forces, F_HAND) and used the framework of the uncontrolled manifold hypothesis to quantify synergies stabilizing F_TOT and F_HAND. Young healthy persons performed steady-state forces with visual feedback and targets for the forces produced by each hand and/or for the total force. We quantified inter-trial and within-a-trial (across time windows) variance components affecting and not affecting F_TOT and F_HAND. Variables with visual feedback, F_TOT or F_HAND, showed force-stabilizing synergies reflected in the structure of variance, while variables without visual feedback failed to show such synergies. The synergies were consistently stronger when the feedback was continuous, compared to when the feedback disappeared when the cursor was inside the target. The results showed a strong dependence between variance that did not affect F_TOT (within the corresponding solution space) and variance that affected each F_HAND across the feedback conditions. Within-a-trial synergy indices were significantly lower than those in the inter-trial analysis. The data are interpreted as reflecting hierarchical control with synergies at both levels of the hierarchy, those that define F_TOT and F_HAND. These synergies get contributions from inter-trial force sharing variability and sensory feedback-based covariation of forces produced by the elements (fingers or hands) along individual trials. Combining inter-trial and within-a-trial analysis of variance may provide an important toolbox to explore cases of impaired control of action stability.