Dopamine neurons in the ventral tegmental area (VTA) are powerful regulators of depression-related behavior. Dopamine neuron activity is altered in chronic stress-based models of depression, but the ...underlying mechanisms remain incompletely understood. Here, we show that mice subject to chronic mild unpredictable stress (CMS) exhibit anxiety- and depressive-like behavior, which was associated with decreased VTA dopamine neuron firing in vivo and ex vivo. Dopamine neuron firing is governed by voltage-gated ion channels, in particular hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. Following CMS, HCN-mediated currents were decreased in nucleus accumbens-projecting VTA dopamine neurons. Furthermore, shRNA-mediated HCN2 knockdown in the VTA was sufficient to recapitulate CMS-induced depressive- and anxiety-like behavior in stress-naïve mice, whereas VTA HCN2 overexpression largely prevented CMS-induced behavioral deficits. Together, these results reveal a critical role for HCN2 in regulating VTA dopamine neuronal activity and depressive-related behaviors.
Previous studies have found that aerobic exercise was more effective in improving vascular endothelial function than resistance training, high-intensity interval training (HIIT), and other types of ...exercise, while the effects between different intensities and durations of aerobic exercise were unclear. Therefore, we performed this meta-analysis to investigate the effects of different intensities and durations of aerobic exercise on the vascular endothelial function of middle-aged and elderly people.
Databases were searched up to April 2021 for studies evaluating the influences of different intensities and durations of aerobic exercise on endothelial function assessed by flow-mediated dilation (FMD) among healthy middle-aged and elderly people. Data were pooled using random-effects models to obtain the weighted mean difference (WMD) and 95% confidence intervals (CIs).
A total of 9 studies involving 221 participants fulfilled the inclusion criteria. Aerobic exercise improved the overall FMD of healthy middle-aged and elderly people WMD, 1.33 (95% CI, 0.37-2.28),
< 0.05. Specifically, vigorous-intensity exercise increased FMD significantly in healthy middle-aged and elderly people WMD, 1.10 (95% CI, 0.27-1.93),
< 0.05, while moderate-intensity exercise had no significant association with FMD WMD, 1.49 (95% CI, -0.62 to 3.60),
= 0.17. In addition, long-term (8 weeks or above) aerobic exercise increased the FMD in healthy middle-aged and elderly people WMD, 1.63 (95% CI, 0.61-2.66),
< 0.05, while one-time acute aerobic exercise had no significant association with FMD of healthy middle-aged and elderly people WMD, 0.89 (95% CI, -1.47 to 3.24),
= 0.46. Specifically, 8 weeks or above of vigorous-intensity exercise increased FMD significantly in healthy middle-aged and elderly people WMD, 1.48 (95% CI, 1.06-1.90),
< 0.01, while 8 weeks or above of moderate aerobic exercise had no significant association with FMD WMD, 1.49 (95% CI, -0.62 to 3.60),
= 0.17.
Aerobic exercise, especially 8 weeks or above of vigorous-intensity aerobic exercise, improved the endothelial function in healthy middle-aged and elderly people.
Current research suggests that continuous aerobic exercise can be effective in improving vascular endothelial function, while the effect between different intensities and durations of exercise is ...unclear. The aim of this study was to explore the effect of different durations and intensities of aerobic exercise on vascular endothelial function in different populations.
Searches were performed in PubMed, Web of Science, and EBSCO databases. We included studies that satisfied the following criteria: 1) randomized controlled trials (RCTs); 2) including both an intervention and control group; 3) using flow-mediated dilation (FMD) as the outcome measure; and 4) testing FMD on the brachial artery.
From 3,368 search records initially identified, 41 studies were eligible for meta-analysis. There was a significant effect of continuous aerobic exercise on improving flow-mediated dilation (FMD) weighted mean difference (WMD), 2.55, (95% CI, 1.93-3.16),
0.001. Specifically, moderate-intensity 2.92 (2.02-3.825),
< 0.001 and vigorous-intensity exercise 2.58 (1.64-3.53),
< 0.001 significantly increased FMD. In addition, a longer duration <12 weeks, 2.25 (1.54-2.95),
< 0.001; ≥12 weeks, 2.74 (1.95-3.54),
< 0.001, an older age age <45, 2.09 (0.78-3.40),
= 0.002; 45 ≤ age <60, 2.25 (1.49-3.01),
< 0.001; age ≥60, 2.62 (1.31-3.94),
< 0.001, a larger basal body mass index (BMI) 20 < BMI < 25, 1.43 (0.98-1.88),
0.001; 25 ≤ BMI < 30, 2.49 (1.07-3.90),
< 0.001; BMI ≥ 30, 3.05 (1.69-4.42),
0.001, and a worse basal FMD FMD < 4, 2.71 (0.92-4.49),
= 0.003; 4 ≤ FMD < 7, 2.63 (2.03-3.23),
< 0.001 were associated with larger improvements in FMD.
Continuous aerobic exercise, especially moderate-intensity and vigorous-intensity aerobic exercise, contributed to improving FMD. The effect of continuous aerobic exercise on improving FMD was associated with duration and participant's characteristics. Specifically, a longer duration, an older age, a larger basal BMI, and a worse basal FMD contributed to more significant improvements in FMD.
: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=341442, identifier CRD42022341442.
There is no clear agreement regarding the ideal rest interval and training intensity to optimize post-activation performance enhancement (PAPE) after barbell squat (BS). Therefore, the aim of this ...study was to investigate the effects of rest interval and training intensity on jumping performance due to PAPE.
Searches were performed in PubMed, Web of Science, and EBSCO databases. We included studies that satisfied the following criteria: (1) eligible studies should be randomized controlled trials; (2) eligible studies should investigate the acute effect of barbell squat-induced PAPE on jump performance; (3) eligible studies should use countermovement jump, squat jump, or vertical jump as the outcome measure.
From 2518 search records initially identified, 19 studies were eligible for meta-analysis. Our meta-analysis results showed that BS had no significant effect on improving jumping performance due to PAPE (Cohen's
= 0.09,
= 0.08). Subgroup analysis showed that rest interval between 0-1 min was detrimental to jumping performance (Cohen's
= -0.33,
< 0.01), while rest intervals between 4-7 min (Cohen's
= 0.31,
< 0.01) and 8-9 min (Cohen's
= 0.26,
= 0.02) provided favorable jumping performance outcomes. In addition, low-intensity and moderate-intensity BS had no significant effect on jump performance, while high-intensity BS showed results consistent with rest interval.
Our study indicated that both low-intensity and moderate-intensity BS failed to induce PAPE, and it is recommended that future studies use high-intensity BS to induce PAPE. A rest interval of 4-9 min had a beneficial impact on jump height, and an interval range of 4-7 min seems to be the best rest interval between conditioning activity and jumping performance.
A growing body of research examines the effect of aerobic exercise on pulse wave velocity (PWV) in middle-aged and elderly people, while findings of available studies were conflicting. The aim of ...this study was to explore the effect of aerobic exercise on PWV in middle-aged and elderly people. Searches were performed in PubMed, Web of Science, and EBSCO databases. Cochrane risk assessment tool was used to evaluate the methodological quality of the included literature. We included studies that satisfied the following criteria: (1) eligible studies should be randomized controlled trials (RCTs); (2) eligible studies should include both an intervention and a control group; (3) eligible studies should use the middle-aged or elderly people as subjects; and (4) eligible studies should use PWV as the outcome measure. From 972 search records initially identified, 11 studies with a total of 12 exercise groups (
n
= 245) and 11 control groups (
n
= 239) were eligible for meta-analysis. There was a significant effect of aerobic exercise on reducing PWV in middle-aged and elderly people weighted mean difference (WMD), –0.75 (95% CI, –1.21 to –0.28),
p
= 0.002. Specifically, a higher intensity vigorous-intensity, –0.74 (–1.34 to –0.14),
p
= 0.02; moderate-intensity, –0.68 (–1.49 to 0.12),
p
= 0.10, a younger age 45 years ≤ age < 60 years, –0.57 (–0.78 to –0.37),
p
< 0.00001; age ≥ 60 years, –0.91 (–2.10 to 0.27),
p
= 0.13, a better health status healthy, –1.19 (–2.06 to –0.31),
p
= 0.008; diseased, –0.32 (–0.64 to –0.01),
p
= 0.04, and a lower basal body mass index (BMI) BMI < 25, –1.19 (–2.06 to –0.31),
p
= 0.008; 25 ≤ BMI < 30, –0.52 (–0.92 to –0.12),
p
= 0.01; BMI ≥ 30, –0.09 (–0.93 to 0.76),
p
= 0.84 were associatedwith larger reductions in PWV. Aerobic exercise, especially vigorous-intensity aerobic exercise, contributed to reducing PWV in middle-aged and elderly people. The effect of aerobic exercise on improving PWV was associated with characteristics of the participants. Specifically, a younger age, a better health status, and a lower basal BMI contributed to more significant reductions in PWV.
Systematic review registration
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022337103
, identifier CRD42022337103.
Abstract
Previous studies have shown that aerobic exercise is an effective way to improve symptoms of Parkinson’s disease (PD). The aim of this study PROSPERO CRD42022340730 was to explore the ...effects of aerobic exercises on balance, gait, motor function, and quality of life in PD patients. Searches were performed in PubMed, Web of Science, and EBSCO electronic databases. The Cochrane risk assessment tool was used to evaluate the methodological quality of the included literature. From 1287 search records initially identified, 20 studies were considered eligible for systematic review and meta-analysis. There was a significant effect of aerobic exercise on improving timed up and go test standardized mean difference (SMD), −0.41 (95% CI, −0.61 to −0.22),
p
< 0.00001, Berg Balance Scale 0.99 (95% CI, 0.76 to 1.23),
p
< 0.00001, stride/step length 0.32 (95% CI, 0.03 to 0.61),
p
= 0.03, gait velocity 0.49 (95% CI, 0.20 to 0.78),
p
= 0.0009, Unified Parkinson’s Disease Rating Scale Part-III -0.40 (95% CI, −0.55 to −0.24),
p
< 0.00001, and 6-minute walking test 0.35 (95% CI, 0.13 to 0.56),
p
= 0.002 in people with PD, but not in step cadence −0.08 (95% CI, −0.43 to 0.27),
p
= 0.65 and Parkinson’s Disease Questionnaire-39 −0.113 (95% CI, −0.39 to 0.13),
p
= 0.32. Aerobic exercise had beneficial effects in improving balance, gait (velocity and stride/step length), and motor function in PD patients. However, aerobic exercise had no significant associations with the step cadence and quality of life in PD patients.
An increasing number of studies have investigated the effect of exercise on flow-mediated dilation (FMD) in people with type 2 diabetes mellitus (T2DM), while the findings were controversial. The ...primary aim of this systematic review and meta-analysis was to investigate the effect of exercise on FMD in T2DM patients, and the secondary aim was to investigate the optimal type, frequency, session duration, and weekly time of exercise for T2DM patients.
Searches were conducted in PubMed, Cochrane Library, Scopus, Web of Science, Embase and EBSCO databases. The Cochrane risk of bias tool (RoB2) in randomized trial and Physiotherapy Evidence Database (PEDro) scale were used to assess the methodological quality of the included studies.
From the 3636 search records initially retrieved, 13 studies met the inclusion criteria. Our meta-analysis revealed that exercise had a significant effect on improving FMD in T2DM patients WMD, 2.18 (95% CI, 1.78-2.58),
< 0.00001,
= 38%, with high-intensity interval training (HIIT) being the most effective intervention type HIIT, 2.62 (1.42-3.82);
< 0.0001; aerobic exercise, 2.20 (1.29-3.11),
< 0.00001; resistance exercise, 1.91 (0.01-3.82),
= 0.05; multicomponent training, 1.49 (0.15-2.83),
= 0.03. In addition, a higher frequency > 3 times, 3.06 (1.94-4.19),
< 0.00001; ≤ 3 times, 2.02 (1.59-2.45),
< 0.00001, a shorter session duration < 60 min, 3.39 (2.07-4.71),
< 0.00001; ≥ 60 min, 1.86 (1.32-2.40),
< 0.00001, and a shorter weekly time ≤ 180 min, 2.40 (1.63-3.17),
< 0.00001; > 180 min, 2.11 (0.82-3.40),
= 0.001 were associated with larger improvements in FMD.
This meta-analysis provides clinicians with evidence to recommended that T2DM patients participate in exercise, especially HIIT, more than 3 times per week for less than 60 min, with a target of 180 min per week being reached by increasing the frequency of exercise.
https://www.crd.york.ac.uk/prospero, identifier CRD42023466575.
Clinical reports suggest that females diagnosed with substance use disorder experience enhanced relapse vulnerability compared with males, particularly during stress. We previously demonstrated that ...a stressor (footshock) can potentiate cocaine seeking in male rats via glucocorticoid-dependent cannabinoid type-1 receptor (CB1R)-mediated actions in the prelimbic prefrontal cortex (PrL-PFC). Here, we investigated the influence of biological sex on stress-potentiated cocaine seeking. Despite comparable self-administration and extinction, females displayed a lower threshold for cocaine-primed reinstatement than males. Unlike males, footshock, tested across a range of intensities, failed to potentiate cocaine-primed reinstatement in females. However, restraint potentiated reinstatement in both sexes. While sex differences in stressor-induced plasma corticosterone (CORT) elevations and defensive behaviors were not observed, differences were evident in footshock-elicited ultrasonic vocalizations. CORT administration, at a dose which recapitulates stressor-induced plasma levels, reproduced stress-potentiated cocaine-primed reinstatement in both sexes. In females, CORT effects varied across the estrous cycle; CORT-potentiated reinstatement was only observed during diestrus and proestrus. As in males, CORT-potentiated cocaine seeking in females was localized to the PrL-PFC and both CORT- and restraint-potentiated cocaine seeking required PrL-PFC CB1R activation. In addition, ex vivo whole-cell electrophysiological recordings from female layer V PrL-PFC pyramidal neurons revealed CB1R-dependent CORT-induced suppression of inhibitory synaptic activity, as previously observed in males. These findings demonstrate that, while stress potentiates cocaine seeking via PrL-PFC CB1R in both sexes, sensitivity to cocaine priming injections is greater in females, CORT-potentiating effects vary with the estrous cycle, and whether reactivity to specific stressors may manifest as drug seeking depends on biological sex.
This study aimed to explore the effects of acute ingestion of caffeine capsules on muscle strength and muscle endurance. We searched the PubMed, Web of Science, Cochrane, Scopus, and EBSCO databases. ...Data were pooled using the weighted mean difference (WMD) and 95% confidence interval. Fourteen studies fulfilled the inclusion criteria. The acute ingestion of caffeine capsules significantly improved muscle strength (WMD, 7.09,
< 0.00001) and muscle endurance (WMD, 1.37;
< 0.00001), especially in males (muscle strength, WMD, 7.59,
< 0.00001; muscle endurance, WMD, 1.40,
< 0.00001). Subgroup analyses showed that ≥ 6 mg/kg body weight of caffeine (WMD, 6.35,
< 0.00001) and ingesting caffeine 45 min pre-exercise (WMD, 8.61,
< 0.00001) were more effective in improving muscle strength, with the acute ingestion of caffeine capsules having a greater effect on lower body muscle strength (WMD, 10.19,
< 0.00001). In addition, the acute ingestion of caffeine capsules had a greater effect in moderate-intensity muscle endurance tests (WMD, 1.76,
< 0.00001). An acute ingestion of caffeine capsules significantly improved muscle strength and muscle endurance in the upper body and lower body of males.
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