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Aging is a major risk factor to develop neurodegenerative diseases and is associated with decreased buffering capacity of the proteostasis network. We investigated the significance of the unfolded protein response (UPR), a major signaling pathway activated to cope with endoplasmic reticulum (ER) stress, in the functional deterioration of the mammalian brain during aging. We report that genetic disruption of the ER stress sensor IRE1 accelerated age-related cognitive decline. In mouse models, overexpressing an active form of the UPR transcription factor XBP1 restored synaptic and cognitive function, in addition to reducing cell senescence. Proteomic profiling of hippocampal tissue showed that XBP1 expression significantly restore changes associated with aging, including factors involved in synaptic function and pathways linked to neurodegenerative diseases. The genes modified by XBP1 in the aged hippocampus where also altered. Collectively, our results demonstrate that strategies to manipulate the UPR in mammals may help sustain healthy brain aging.

Optimal postural control improves performance and reduces the risk of injury in futsal. In this context, wearable accelerometers may detect velocity changes of the centre of mass during a task, enabling the analysis of postural control in different environments. This work aimed to determine the influence of vision and dominance on unipodal static postural balance in non-professional athletes. Twenty-four university male futsal players performed a unipodal balance test to assess their body sway using a triaxial accelerometer. To assess dominance, the preferred limb for kicking the ball was considered, while vision was manipulated by asking participants to close their eyes during the test. Root mean square (RMS) and sample entropy (SaEn) of centre of mass variables were analysed. For statistical analysis, a multivariate analysis of variance model was used. Our results suggest an effect of vision, but not of dominance nor the interaction between vision and limb dominance. Specifically, a higher-acceleration RMS in the mediolateral axis was observed, as well as an increased SaEn in the three axes. To conclude, unipodal postural demand in futsal players under visual input suppression was not influenced by their limb dominancy [ABSTRACT FROM AUTHOR]

Background: This systematic review aimed to discern the relationships between muscle morphology, architecture, and quality with sprint cycling performance while considering the multifaceted nature of these relationships across diverse studies. Methods: Employing the PRISMA guidelines, an exhaustive search was performed across four primary databases: MEDLINE/PubMed, Web of Science, CINAHL Complete, and SPORTDiscus. The Methodological Index For Non-Randomised Studies (MINORS) was used to assess the methodological quality of the included studies. Out of 3971 initially identified records, only 10 studies met the eligibility criteria. Results: These investigations underscored the robust relationship of quadriceps muscle volume with peak power output (R2 from 0.65 to 0.82), suggesting its pivotal role in force production. In muscle architecture, the pennation angle and fascicle length showed varied associations with performance. Furthermore, muscle quality, as denoted by echo intensity, showed preliminary evidence of a potential inverse relationship with performance. The methodological quality assessment revealed varied scores, with the most consistent reporting on the aim, endpoints, and inclusion of consecutive patients. However, limitations were observed in the prospective calculation of study size and unbiased assessment of study endpoints. Conclusion: Our findings indicate that muscle volume is a major determinant of sprint cycling performance. Muscle architecture and quality also impact performance, although in a more intricate way. The review calls for standardised methodologies in future research for a more comprehensive understanding and comparability of results. PROSPERO registration number: CRD42023432824 (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=432824). Key Points: • Muscle size matters: greater muscle volume and cross-sectional area correlate strongly with peak power output, emphasising the importance of muscle size in sprint cycling. • Pennation angle positively correlates with peak power output, but varied associations indicate the existence of other influencing factors, highlighting the complexity of muscle architecture in sprint performance. • Preliminary evidence suggests lower echo intensity, indicating higher muscle quality, may be linked to better sprint performance, urging further exploration of this relationship in athletes. [ABSTRACT FROM AUTHOR]

Context: In human movement analysis, normalization of a surface electromyography signal is a crucial step; therefore, parameter selection for this procedure must be adequately justified. The aim of this research was to determine the variability of electromyography signals in eccentric hamstring contraction under different normalization parameters. Design: Cross-sectional study. Methods: Nine university rugby players (age 21.50 [3.61] y; body mass index 21.50 [4.95]) and no history of recent hamstring injury. Values from maximum voluntary isometric contraction protocol and task related (ie, Nordic hamstring exercise) were used for surface electromyography signal normalization. Intersubject and intrasubject variation coefficients were used for normalization method variability and for signal reproducibility, respectively. Results: Intrasubject variation coefficient value indicates acceptable reproducibility of surface electromyography (less than 12%) for all normalization procedures. Lower values of intersubject variation coefficient value were achieved for normalization procedures using task-related values. Conclusion: Parameters extracted from task execution provided less variability for surface electromyography amplitude normalization in eccentric hamstring muscle contractions. [ABSTRACT FROM AUTHOR]

To determine the effect of sensory perturbations on static postural control in older people with type 2 diabetes mellitus by comparing postural outcomes of people with and without diabetic neuropathy using a Wii Balance Board (WBB). Static postural balance assessments were performed in 31 participants: nine with type 2 diabetes mellitus; 12 with diabetic neuropathy; and 10 non-diabetic controls. Participants stood on the WBB under sensory perturbations (visual and proprioceptive). Body balance was analysed using centre of pressure ellipse area, mean velocity, and sample entropy. The effects of within-participant factors, sensory perturbations and the between-participants factor 'group' on outcomes were analysed using a multivariate analysis of variance model. Type 2 diabetes mellitus participants with and without neuropathy showed altered postural performance under sensory perturbations compared to non-diabetic participants. Moreover, participants with diabetic neuropathy showed impaired postural performance when one perceptual system was disturbed. Finally, participants with type 2 diabetes mellitus without neuropathy decreased their postural performance when both sensory disturbances were present. The Wii Balance Board can be a useful alternative for balance impairment screening related to diabetic neuropathy and contribute as an affordable source of insight in early interventions in integral diabetes care. Older people with diabetic peripheral neuropathy depend on visual and somatosensory cues to keep their static postural balance. Static balance assessment using the Wii Balance Board allows the identification of alterations in postural performance in participants with diabetes. This low-cost method used can be considered as a complement to integral diabetes care. [ABSTRACT FROM AUTHOR]