Effects of Exercise Training Under Hypoxia versus Normoxia on Cognitive Function in Clinical and Non-Clinical Populations: A Systematic Review and Meta-analysis.

OBJECTIVE: To compare the effects of exercise training under hypoxia versus normoxia on cognitive function in clinical and non-clinical populations. DATA SOURCES: From inception to June 13th, 2022, a systematic search was performed on PubMed, Web of Science, Embase, Scopus, and Cochrane Central Register of Controlled Trials. STUDY SELECTION: Randomized controlled trials comparing the effects of exercise under hypoxic vs normoxic on cognition in clinical and non-clinical populations were included. The systematic search generated 14,894 relevant studies, of which 12 were finally included. DATA EXTRACTION: Two reviewers independently extracted data from included studies. Results were expressed as standardized mean difference (SMD). Each included study was assessed using the Cochrane Risk of Bias 1.0 (RoB1.0) tool. Finally, the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system was used to rate the certainty of evidence for each outcome. DATA SYNTHESIS: Overall, 12 studies with a total of 338 participants met the inclusion criteria. The pooled results suggested that hypoxia exercise had a small but not statistically significant positive effect on overall cognitive function (SMD=0.064, 95% confidence interval (CI): -0.156-0.284, P=.567, very low-certainty evidence), when compared with normoxic exercise. Regarding the domain-specific cognitive functions, there was a medium and significant positive effect on memory (SMD=0.594, 95% CI: 0.068 to 1.120, P=.027, very low-certainty evidence), while effects on visuospatial function (SMD=0.490, 95% CI: -0.030 to 1.010, P=.065, very low-certainty evidence), attention (SMD=0.037, 95% CI: -0.340 to 0.414, P=.847, very low-certainty evidence), executive function (SMD=0.096, 95% CI: -0.268 to 0.460, P=.605, very low-certainty evidence), and processing speed (SMD=-0.145, 95% CI: -0.528 to 0.239, P=.459, very low-certainty evidence) were not statistically significant. CONCLUSIONS: The current pooled results revealed that hypoxic exercise was related to improved cognitive performance. Nevertheless, exercise under hypoxia did not have a significant advantage in cognitive promotion when compared with exercise under normoxia.

Automated assessment of balance: A neural network approach based on large-scale balance function data.

Balance impairment (BI) is an important cause of falls in the elderly. However, the existing balance estimation system needs to measure a large number of items to obtain the balance score and balance level, which is less efficient and redundant. In this context, we aim at building a model to automatically predict the balance ability, so that the early screening of large-scale physical examination data can be carried out quickly and accurately. We collected and sorted out 17,541 samples, each with 61-dimensional features and two labels. Moreover, using this data a lightweight artificial neural network model was trained to accurately predict the balance score and balance level. On the premise of ensuring high prediction accuracy, we reduced the input feature dimension of the model from 61 to 13 dimensions through the recursive feature elimination (RFE) algorithm, which makes the evaluation process more streamlined with fewer measurement items. The proposed balance prediction method was evaluated on the test set, in which the determination coefficient (R2) of balance score reaches 92.2%. In the classification task of balance level, the metrics of accuracy, area under the curve (AUC), and F1 score reached 90.5, 97.0, and 90.6%, respectively. Compared with other competitive machine learning models, our method performed best in predicting balance capabilities, which is especially suitable for large-scale physical examination.

Modulation of entorhinal cortex-hippocampus connectivity and recognition memory following electroacupuncture on 3×Tg-AD model: Evidence from multimodal MRI and electrophysiological recordings.

Memory loss and aberrant neuronal network activity are part of the earliest hallmarks of Alzheimer's disease (AD). Electroacupuncture (EA) has been recognized as a cognitive stimulation for its effects on memory disorder, but whether different brain regions or neural circuits contribute to memory recovery in AD remains unknown. Here, we found that memory deficit was ameliorated in 3×Tg-AD mice with EA-treatment, as shown by the increased number of exploring and time spent in the novel object. In addition, reduced locomotor activity was observed in 3×Tg-AD mice, but no significant alteration was seen in the EA-treated mice. Based on the functional magnetic resonance imaging, the regional spontaneous activity alterations of 3×Tg-AD were mainly concentrated in the accumbens nucleus, auditory cortex, caudate putamen, entorhinal cortex (EC), hippocampus, insular cortex, subiculum, temporal cortex, visual cortex, and so on. While EA-treatment prevented the chaos of brain activity in parts of the above regions, such as the auditory cortex, EC, hippocampus, subiculum, and temporal cortex. And then we used the whole-cell voltage-clamp recording to reveal the neurotransmission in the hippocampus, and found that EA-treatment reversed the synaptic spontaneous release. Since the hippocampus receives most of the projections of the EC, the hippocampus-EC circuit is one of the neural circuits related to memory impairment. We further applied diffusion tensor imaging (DTI) tracking and functional connectivity, and found that hypo-connected between the hippocampus and EC with EA-treatment. These data indicate that the hippocampus-EC connectivity is responsible for the recognition memory deficit in the AD mice with EA-treatment, and provide novel insight into potential therapies for memory loss in AD.