Low-intensity exercise with blood flow restriction (LI BFR) has been shown to release substances that play a key role in neuroplasticity and may be effective in improving rehabilitation outcomes in patients with neurodegenerative diseases. Researchers suggest that LI BFR engages high-threshold motor units even during low-intensity exercise, leading to increased motor unit end-state variability and a rapid onset of neuromuscular fatigue. However, the amplitude-frequency characteristics and motor unit recruitment strategies during LI BFR are not well understood. The aim of this study was to investigate the effects of blood flow restriction on motor unit activation patterns during low-intensity exercise to elucidate the physiological mechanisms underlying this novel training approach. Participants with a mean age of 33 years were subjected to blood flow restriction during isometric wrist flexion. High-density surface EMG (HD sEMG) activity was recorded from both the flexor carpi radialis and palmaris longus muscles. The study shows that blood flow restriction significantly shifted motor unit activation to high threshold motor units. These findings highlight the need to investigate the long-term effects of LI BFR on motor unit coordination in clinical populations.

Neuropathic pain is a condition affecting the quality of life of a substantial part of the population, but biomarkers and treatment options are still limited. While this type of pain is caused by nerve damage, in which lipids play key roles, lipidome alterations related to nerve injury remain poorly studied. Here, we assessed blood lipidome alterations in a common animal model, the rat sciatic nerve crush injury. We analyzed alterations in blood lipid abundances between seven rats with nerve injury (NI) and eight control (CL) rats in a time-course experiment. For these rats, abundances of 377 blood lipid species were assessed at three distinct time points: immediately after, two weeks, and five weeks post injury. Although we did not detect significant differences between NI and CL at the first two time points, 106 lipids were significantly altered in NI five weeks post injury. At this time point, we found increased levels of triglycerides (TGs) and lipids containing esterified palmitic acid (16:0) in the blood plasma of NI animals. Lipids containing arachidonic acid (20:4), by contrast, were significantly decreased after injury, aligning with the crucial role of arachidonic acid reported for NI. Taken together, these results indicate delayed systematic alterations in fatty acid metabolism after nerve injury, potentially reflecting nerve tissue restoration dynamics.

Differential abundance analysis (DAA) is a critical task in microbiome research aimed at identifying microbial signatures that reliably characterize groups. Research suggests that microbiome systems are relatively stable and resilient, yet even small changes under certain conditions can trigger dysbiosis. The high dimensionality of microbiome datasets exacerbates the challenge of detecting such changes by posing a multiple comparison problem that requires hypothesis filtration. Standard filtration using multiple comparison correction procedures is designed for scenarios with a high number of true positives and is often too conservative for microbiome data, where the proportion of true signals can be very low. Therefore, there is a substantial need for hypothesis filtration methods tailored to microbiome data. Confidence intervals (CIs) for between-group differences offer a powerful alternative to p-value filtration, as their range simultaneously conveys information about the significance, potential magnitude, and direction of the effect, as well as the certainty of the estimate itself. Microbial data can be adequately modeled using a negative binomial (NB) distribution, and its location parameter can be robustly estimated with the Hodges–Lehmann estimator (HLE). Using synthetic and experimental data, we demonstrate that hypothesis filtration based on CIs for the two-sample HLE is a robust method for comparing microbial data. Our analysis demonstrates that the HLE-CI approach provides the same level of precision as filtration using multiple-adjustment methods while achieving significantly higher recall in microbiome DAA. The results of this study suggest that HLE-CI-based filtration can be an effective step in the search for microbiome biomarkers.

Transcutaneous spinal cord stimulation (tSCS) is a promising noninvasive alternative to epidural stimulation. However, further studies are needed to clarify how tSCS affects postural control. The aim of this study was to investigate the effect of transcutaneous cervical spinal cord stimulation on postural stability in healthy participants via computerized stabilization. The center of pressure and the frequency spectrum of the statokinesiogram were assessed in 14 healthy volunteers under tSCS conditions with frequencies of 5 Hz or 30 Hz, subthreshold or suprathreshold stimulus strength, open or closed eyes, and hard or soft surfaces in various combinations. The results revealed that not all the changes in the center of the pressure oscillations reached statistical significance when the tSCS was used. However, tSCS at a frequency of 30 Hz with a suprathreshold stimulus strength improved postural stability. The use of subthreshold or suprathreshold tSCS at 5 Hz led to a shift of 60% of the signal power to the low-frequency range, indicating activation of the vestibular system. With tSCS at 30 Hz, the vestibular component remained dominant, but a decrease in the proportion of high-frequency oscillations was observed, which is associated with muscle proprioception. Thus, transcutaneous electrical stimulation of the cervical spinal cord may be an effective method for activating spinal cord neural networks capable of modulating postural control.

The goal of this work was to study the influence of daily 3-hr vibrostimulation of the supporting zones of the foot and 3-hr of usual locomotion on the functional state of the soleus, gastrocnemius, and tibial anterior muscles in rats after 7 and 14 days of hindlimb unloading. After 7 days of unloading the soleus weight decreased, while the weight of gastrocnemius and tibial anterior remained unchanged. After 14 days of hindlimb unloading a weight reduction was observed in all studied muscles. Vibrostimulation of the foot and supporting afferentation prevented the loss of weight in gastrocnemius and tibial anterior during the first week of unloading and reduced the negative effect of hindlimb unloading in 14 days. Our results demonstrate that the amplitude of the M-response after 7 days of hindlimb unloading was decreased predominantly in soleus as compared to gastrocnemius and tibial anterior. By the 14 day we observed restoration of the amplitude of the M-response in gastrocnemius and tibial anterior, and the increased amplitude of the M-response in soleus. Different techniques for foot stimulation in rats during hindlimb unloading demonstrated the positive effect in regard to M-response restoration — the amplitude of the M-response was increased in all studied muscles. Thus, our results demonstrate that foot vibrostimulation or supporting afferentation can completely prevent atrophy caused by hindlimb unloading in gastrocnemius and tibial anterior and decrease atrophy in soleus in rats.