Forced Running Endurance Is Influenced by Gene(s) on Mouse Chromosome 10

Acknowledgments The authors wish to acknowledge technical assistance from Mrs. Indrė Libnickienė and intellectual input from Dr. David A. Blizard. This research was funded by the European Social Fund under the Global Grant measure. Grant VP1-3.1-ŠMM-07-K-02-057 was awarded to AL.Peer reviewedPublisher PD

Exploring the Preliminary Effects of Resistance Training on Total Brain-Derived Neurotrophic Factor (BDNF) Levels in Elderly Individuals: A Pilot Study

Background: Studies have shown that exercise modulates brain-derived neurotrophic factor (BDNF) levels, and resistance training, in particular, has received increasing attention for its potential to enhance BDNF production. Most studies investigating exercise-induced BDNF changes have focused on free or mature BDNF, while the measurement of total BDNF, encompassing both proBDNF and mature BDNF, may provide a more comprehensive understanding of BDNF regulation. This pilot study aimed to explore the preliminary effects of resistance training on total BDNF levels in elderly individuals participating in a resistance training program. Methods: A small sample of participants (n=6) was recruited and engaged in a structured resistance training program for 12 weeks, with 6 participants in a control group. Total BDNF levels were measured at baseline and post-intervention using reliable laboratory assessments. Additionally, an isokinetic dynamometer was used to determine muscle strength to explore the effect of the resistance training program on muscle performance. Results: The findings revealed a significant increase in total BDNF levels following the 12 week resistance training intervention (p<0.05). However, improvements in physical performance measures, knee extension peak torque and isometric maximal voluntary contraction, were not observed. Conclusion: In conclusion, this pilot study provides preliminary evidence of the positive effects of a 12 week resistance training intervention on total BDNF levels. The measurement of total BDNF levels serves as an important marker in assessing the response to resistance training. Further research with larger sample sizes and longer intervention periods is warranted to further explore the relationship between resistance training and total BDNF levels and to confirm these preliminary findings. Understanding the impact of resistance training on total BDNF levels can have implications for optimizing training programs and potentially improving exercise-related outcomes. Keywords: muscle strength, exercise, brain-derived neurotrophic factor, neuroplasticity, healthy ageing

Myostatin dysfunction does not protect from fasting-induced loss of muscle mass in mice

Peer reviewedPublisher PD

Impact of reduced citrate synthase activity on endurance training-induced adaptation

Research object: impact of reduced citrate synthase activity on endurance training-induced adaptation. Research aim – identify impact of reduced citrate synthase activity on endurance training-induced adaptation. Research goals: 1. Identify and compare B6 mice strain and F1 hybrid mice endurance results before and after endurance training. 2. Identify and compare trained B6 and F1 mice gastrocnemius muscle and heart weight and citrate synthase acitvity in gastrocnemius muscle. 3. Identify and compare trained B6 and F1 mice blood lipid profile. Hypothesis – reduced citrate synthase activity can adversely affect running endurance. Conclusions: 1. Reduced citrate synthasis activity can lead to lower endurance in F1 hybrid mice. 2. Trained F1 hybrid mice citrate synthase acitivity in gastrocnemius muscle was significantly lower than the trained B6 mice. F1 mice gastrocnemius muscle and heart weight was comparable to trained B6 mice. 4. Trained F1 hybrid female mice total blood cholesterol and HDL level was significantly higher than the trained B6 female mice. B6 mice blood triglyceride level was comparable to F1 hybrid mice

Mirror visual feedback impact on abductor pollicis brevis muscle electrical activity in the stroke affected arm

Research aim – identify mirror visual feedback impact on abductor pollicis brevis muscle activity in the stroke affected arm. Research goals: 1.Compare impact of bimanual thumb opposition movement without mirror visual feedback and with non-affected hand mirror visual feedback. 2.Compare impact of bimanual thumb opposition movement without mirror visual feedback and with affected hand mirror visual feedback. 3.A cross-check of the affected and non-affected hand reflection in the mirror impact on abductor pollicis brevis muscle activity in the stroke affected arm. 4.Comparing abductor pollicis brevis muscle electrical activity results between healthy persons and stroke patients. Hypothesis – we hypothetisize that abductor pollicis brevis muscle activity in the stroke affected arm will be higher when the movements are performing with visual mirror feedback than without it. Results. There was no significant stroke patients abductor pollicis brevis muscle activity difference between the non-affected hand mirror visual feedback and affected hand mirror visual feedback task results. There was a significant higher (p<0,05) abductor pollicis brevis muscle activity when was observed the non-affected hand reflection in the mirror than task without mirror visual feedback. Meanwhile there was no significant difference abductor pollicis brevis muscle activity when was observed affected hand reflection in the mirror than task without mirror visual feedback. There was a significant higher (p<0,05) muscle activity of health subjects than stroke patients. There was a significant higher (p<0,05) mean frequency of the abductor pollicis brevis muscle in the stroke patients observing non-affected hand reflection in the mirror than in the health subjects observing the same reflection. Conlusions: 1.Observing thumb opposition of the non-affected arm reflection in the mirror, abductor pollicis brevis muscle activity of the affected arm is higher than performing thumb opposition without the mirror visual feedback. 2.Observing thumb opposition of the affected arm reflection in the mirror, abductor pollicis brevis muscle activity of the affected arm not differ between activity when the movements are performing without mirror visual feedback. 3.Observing thumb opposition of the affected arm reflection in the mirror are seen decreasing tendency of abductor pollicis brevis muscle activity than observing non-affected arm reflection in the mirror. 4.Observing non-affected hand reflection and observing affected hand reflection, and observing the movements without visual mirror feddback, stroke patients abductor pollicis brevis muscle activity in the affected hand was lower than healthy persons

Exploring the preliminary effects of resistance training on total brain-derived neurotrophic factor (BDNF) levels in elderly individuals: a pilot study

Background: Studies have shown that exercise modulates brain-derived neurotrophic factor (BDNF) levels, and resistance training, in particular, has received increasing attention for its potential to enhance BDNF production. Most studies investigating exercise-induced BDNF changes have focused on free or mature BDNF, while the measurement of total BDNF, encompassing both proBDNF and mature BDNF, may provide a more comprehensive understanding of BDNF regulation. This pilot study aimed to explore the preliminary effects of resistance training on total BDNF levels in elderly individuals participating in a resistance training program. Methods: A small sample of participants (n=6) was recruited and engaged in a structured resistance training program for 12 weeks, with 6 participants in a control group. Total BDNF levels were measured at baseline and post-intervention using reliable laboratory assessments. Additionally, an isokinetic dynamometer was used to determine muscle strength to explore the effect of the resistance training program on muscle performance. Results: The findings revealed a significant increase in total BDNF levels following the 12 week resistance training intervention (p<0.05). However, improvements in physical performance measures, knee extension peak torque and isometric maximal voluntary contraction, were not observed. Conclusion: In conclusion, this pilot study provides preliminary evidence of the positive effects of a 12 week resistance training intervention on total BDNF levels. The measurement of total BDNF levels serves as an important marker in assessing the response to resistance training. Further research with larger sample sizes and longer intervention periods is warranted to further explore the relationship between resistance training and total BDNF levels and to confirm these preliminary findings. Understanding the impact of resistance training on total BDNF levels can have implications for optimizing training programs and potentially improving exercise-related outcomes. Keywords: muscle strength, exercise, brain-derived neurotrophic factor, neuroplasticity, healthy ageing

Relationships between weekly changes in salivary hormonal responses and load measures during the pre-season phase in professional male basketball players

The aim of this study was to assess the relationships between weekly changes in external and internal load considered separately and jointly and salivary hormonal responses during the pre-season phase in professional male basketball players. Twenty-one professional male basketball players (mean±standard deviation, age: 26.2±4.9 years; height: 198.7±6.7 cm; body mass: 93.2±10.0 kg) were assessed during 5 weeks of the pre-season phase. External load was measured using microsensors and reported as PlayerLoad (PL) and PL/ min. Internal load was calculated using the session rating of perceived exertion scale (sRPE-load), summated heart rate zones (SHRZ) and percentage of maximal heart rate (%HRmax). Salivary hormone responses were monitored weekly by measuring testosterone (T), cortisol (C), and their ratio (T:C). The relationships between weekly changes in load measures considered separately and jointly and hormonal responses were assessed using linear mixed model analysis. No significant (p > 0.05) relationships were evident between weekly changes in T, C or T:C with external and internal load measures considered separately (R2-conditional = < 0.001–0.027) or jointly (R2-conditional = 0.028–0.075). Factors other than measured loads might be responsible for weekly changes in hormonal responses and therefore external and internal load measures cannot be used to anticipate weekly hormonal responses during the pre-season phase in professional basketball players

Caloric restriction per se rather than dietary macronutrient distribution plays a primary role in metabolic health and body composition improvements in obese mice

Caloric restriction (CR) is of key importance in combating obesity and its associated diseases. We aimed to examine effects of dietary macronutrient distribution on weight loss and metabolic health in obese mice exposed to CR. Male C57BL/6J mice underwent diet-induced obesity for 18 weeks. Thereafter mice were exposed to a 6-week CR for up to 40% on either low-fat diet (LFD; 20, 60, 20% kcal from protein, carbohydrate, fat), low-carb diet (LCD; 20, 20, 60% kcal, respectively) or high-pro diet (HPD; 35, 35, 30% kcal, respectively) (n = 16 each). Ten mice on the obesogenic diet served as age-matched controls. Body composition was evaluated by tissue dissections. Glucose tolerance, bloods lipids and energy metabolism were measured. CR-induced weight loss was similar for LFD and LCD while HPD was associated with a greater weight loss than LCD. The diet groups did not differ from obese controls in hindlimb muscle mass, but showed a substantial decrease in body fat without differences between them. Glucose tolerance and blood total cholesterol were weight-loss dependent and mostly improved in LFD and HPD groups during CR. Blood triacylglycerol was lowered only in LCD group compared to obese controls. Thus, CR rather than macronutrient distribution in the diet plays the major role for improvements in body composition and glucose control in obese mice. Low-carbohydrate-high-fat diet more successfully reduces triacylglycerol but not cholesterol levels compared to isocaloric high-carbohydrate-low-fat weight loss diet

Myostatin dysfunction does not protect from fasting-induced loss of muscle mass in mice

OBJECTIVES: The aim of the study was to investigate if myostatin dysfunction can ameliorate fasting-induced muscle wasting. METHODS: 18-week old males from Berlin high (BEH) strain with myostatin dysfunction and wild type myostatin (BEH+/+) strain were subjected to 48-h food deprivation (FD). Changes in body composition as well as contractile properties of soleus (SOL) and extensor digitorum longus (EDL) muscles were studied. RESULTS: BEH mice were heavier than BEH+/+ mice (56.0±2.5 vs. 49.9±2.8 g, P0.05), but only BEH mice experienced wasting of the gastrocnemius, tibialis anterior and plantaris muscles. FD induced a marked decrease in specific muscle force of SOL. EDL of BEH mice tended to be protected from this decline. CONCLUSION: Myostatin dysfunction does not protect from loss of muscle mass during fasting

Inflammatory blood biomarker kynurenine is linked with elevated neuroinflammation and neurodegeneration in older adults: evidence from two 1H-MRS post-processing analysis methods

Rationale and Objectives: Pro-inflammatory processes have been argued to play a role in conditions associated with cognitive decline and neurodegeneration, like aging and obesity. Only a limited number of studies have tried to measure both peripheral and central biomarkers of inflammation and examined their interrelationship. The primary aim of this study was to examine the hypothesis that chronic peripheral inflammation would be associated with neurometabolic changes that indicate neuroinflammation (the combined elevation of myoinositol and choline), brain gray matter volume decrease, and lower cognitive functioning in older adults. Materials and Methods: Seventy-four older adults underwent bio-impedance body composition analysis, cognitive testing with the Montreal Cognitive Assessment (MoCA), blood serum analysis of inflammatory markers interleukin-6 (IL-6) and kynurenine, magnetic resonance imaging (MRI), and proton magnetic resonance spectroscopy (1H-MRS) of the brain. Neurometabolic findings from both Tarquin and LCModel 1H-MRS post-processing software packages were compared. The regions of interest for MRI and 1H-MRS measurements were dorsal posterior cingulate cortex (DPCC), left hippocampal cortex (HPC), left medial temporal cortex (MTC), left primary sensorimotor cortex (SM1), and right dorsolateral prefrontal cortex (DLPFC). Results: Elevated serum kynurenine levels were associated with signs of neuroinflammation, specifically in the DPCC, left SM1 and right DLPFC, and signs of neurodegeneration, specifically in the left HPC, left MTC and left SM1, after adjusting for age, sex and fat percentage (fat%). Elevated serum IL-6 levels were associated with increased Glx levels in left HPC, left MTC, and right DLPFC, after processing the 1H-MRS data with Tarquin. Overall, the agreement between Tarquin and LCModel results was moderate-to-strong for tNAA, tCho, mIns, and tCr, but weak to very weak for Glx. Peripheral inflammatory markers (IL-6 and kynurenine) were not associated with older age, higher fat%, decreased brain gray matter volume loss or decreased cognitive functioning within a cohort of older adults. Conclusion: Our results suggest that serum kynurenine may be used as a peripheral inflammatory marker that is associated with neuroinflammation and neurodegeneration, although not linked to cognition. Future studies should consider longitudinal analysis to assess the causal inferences between chronic peripheral and neuroinflammation, brain structural and neurometabolic changes, and cognitive decline in aging