Search

Background: BDNF is known to induce neuroplasticity and low circulating levels have been related to neuronal loss in older persons. Physical exercise is thought to trigger BDNF-induced neuroplasticity, but conflicting observations have been reported regarding the effects of resistance training on circulating BDNF in the elderly. These conflicting observations might reflect dose-and gender-specific differences., Method: Fifty-six apparently healthy elderly (68 ± 5 years) participants were randomized to 12 weeks of resistance training (3×/week) at either high-resistance (HIGH, 8 Males, 10 Females, 2 × 10-15 repetitions at 80% 1 RM), low-resistance (LOW, 9 Males, 10 Females, 1 × 80-100 repetitions at 20% 1 RM), or mixed low-resistance (LOW+, 9 Males, 10 Females, 1 × 60 repetitions at 20% 1 RM followed by 1 × 10-20 repetitions at 40% 1 RM). Serum was collected for BDNF assay at baseline and after 12 weeks (24 h-48 h after the last training)., Results: 12 weeks of LOW+ exercise significantly increased BDNF levels in male (from 34.9 ± 10.7 ng/mL to 42.9 ± 11.9 ng/mL, time × group interaction p=0.013), but not in female participants. No significant change was observed in HIGH or LOW, neither in male nor female subjects., Conclusion: Our results show that only the mixed-low-resistance training program with a very high number of repetitions at a sufficiently high external resistance was able to increase circulating BDNF in older male participants. Training to volitional fatigue might be necessary to obtain optimal results. Additional studies are needed to unravel the underlying mechanisms, as well as to confirm the observed gender difference., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Ageing is associated with a chronic low-grade inflammatory profile (CLIP). Physical exercise could circumvent the deleterious effects of CLIP by influencing circulating inflammatory mediators and neurotrophic growth factors. This study aimed at assessing whether 12 weeks of progressive strength training (PST) influences circulating brain-derived neurotrophic factor (BDNF), interleukin (IL)-6 and IL-10 in elderly individuals. Forty community-dwelling persons aged 62-72 years participated. Twenty participants were assigned to 12-week PST (70-80 % of maximal strength, three times per week). Matched control individuals (n = 20) maintained daily activity levels. Serum was collected for BDNF, IL-6 and IL-10 assay from all participants before and after 12 weeks (for PST subjects 24-48 h after the last training). In PST, muscle strength was significantly improved (+49 % for leg extension, p = 0.039), and basal IL-6 levels significantly reduced (p = 0.001), which remained unchanged in control (p = 0.117). No significant change in BDNF was observed in PST subjects (p = 0.147) or control (p = 0.563). IL-10 was below the detection limit in most subjects. Gender and health status did not influence the results. Our results show that after 12-week PST, muscle performance improved significantly, and basal levels of IL-6 were significantly decreased in older subjects. However, serum BDNF was not altered. The lack of an observable change in BDNF might be due to a short-lived BDNF response, occurring acutely following exercise, which might have been washed out when sampling. Furthermore, blood levels of BDNF may not reflect parallel increases that occur locally in the brain and muscle. These hypotheses need confirmation by further studies.

Purpose: Serum brain-derived neurotrophic factor (BDNF) is known to increase with exercise. This increase is believed to originate from the brain and it is suggested that monoamines are involved in BDNF regulation. Heat exposure could influence the supposed BDNF output from the brain. Therefore, we hypothesized that administration of a selective serotonin reuptake inhibitor could influence the exercise-induced increase in BDNF, and that peripheral BDNF will be higher when exercise is performed in the heat., Methods: Eleven well-trained males performed 4 experimental trials on a cycle ergometer with citalopram or placebo treatment (20 mg in 12 h) in an environmental temperature of 18°C or 30°C. Blood samples (BDNF and cortisol) were taken at 4 time points: at rest, after 60 min at 55% W(max), after a time trial of 30 min at 75% W(max) and following 15 min of recovery. Heart rate and core temperature were measured., Results: Performance on the time trial was 20% worse in 30°C compared to 18°C (p<0.01), without influence of citalopram. Serum BDNF was found to be lower under citalopram treatment, while basal cortisol levels were increased (p<0.05). Exercise triggered an increase in both BDNF and cortisol (p<0.001). BDNF followed the same pattern as core temperature during exercise, with higher levels of both variables in 30°C. Cortisol was also increased in 30°C compared to temperate conditions (p<0.01)., Conclusion: Exercise caused a rise in serum BDNF and cortisol. This increase was enhanced with exercise in the heat. Since permeability of the blood-brain barrier increases with exercise in the heat, the hypothesis was raised that this causes a higher cerebral output of BDNF. Serotonergic stimulation did not increase peripheral BDNF, which was even lower with citalopram administration. Future research should focus on mechanisms behind BDNF increase with exercise., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The purpose of the study was to examine the acute effect of a strength training session on brain-derived neurotrophic factor and insulin-like growth factor 1. Furthermore, the influence of a 10-week strength training program on brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1) resting levels and memory performance was studied. Fifteen untrained subjects followed a strength training program for 10 weeks. Eight control subjects remained physically inactive. To study the influence of an acute strength training session, blood samples were taken before and after the sixth and 30th sessions. Training effects were evaluated by taking blood samples at rest before and following the training program. Short- and mid-term memories were assessed using the digit span and a recall of images test. BDNF, IGF-1 and its binding protein (IGFBP-3) were measured in serum samples. Data were analyzed (p < 0.05) using a mixed design ANOVA model, Duncan's multiple range post hoc tests, and Pearson's correlation. A single strength training session did not influence BDNF and IGF-1 concentrations. No effect of the strength training period on BDNF, IGF-1, and IGFBP-3 was found. No correlation was found between peripheral BDNF and IGF-1. Short-term memory improved in both the experimental and control groups, but no difference between groups was present. Mid-term memory did not improve following the 10 weeks of training. A period of strength training in sedentary subjects does not significantly change the growth factors or memory function compared to a control group. Also, BDNF and IGF-1 are not acutely influenced by a training session. Further research should focus on the beneficial role of physical exercise in neurodegenerative diseases.

Purpose: To examine the influence of a selective noradrenaline reuptake inhibitor (SNRI) on the exercise-induced increase in circulating brain-derived neurotrophic factor (BDNF)., Methods: In a double-blind, placebo-controlled, crossover design, 11 young, healthy male subjects were treated with either placebo or reboxetine. On each occasion, they performed a 60-min cycling exercise at 55% of their maximal power output (Wmax) followed by a time trial (TT) at 75% of Wmax. HR and ratings of perceived exertion were measured. Blood samples were taken at four time points., Results: An increase in serum BDNF was found after exercise without any influence of drug administration on BDNF levels. Serum BDNF returned to resting levels after 15 min of recovery. Time trial (TT) performance was significantly worse after reboxetine intake. Serum cortisol increased in both trials during and after exercise and was significantly higher in the reboxetine trial. Also, HR was increased with reboxetine intake, probably because of the sympathomimetic effect of SNRI. Midterm memory was significantly impaired after the exercise protocol without difference between reboxetine and placebo trial., Conclusions: The administration of an SNRI has no effect on the exercise-induced increase in BDNF. However, effects were seen on serum cortisol, HR, and memory. Future research should focus on the effect of regular exercise training in combination with several reuptake inhibitors in both healthy and depressed subjects on BDNF and memory.