Gender differences in barriers to participation in after-school physical activities and related factors in Australian schoolchildren: A cross-sectional study.

INTRODUCTION: This study investigated the gender differences in reported barriers to participation in after-school physical activity (PA) and related health and socio-behavioural factors in Australian schoolchildren. METHODS: 5001 students aged 10 to 16 years completed the health and well-being survey in 2014 indicating that they would like to participate in after-school PA. Negative binomial regression models, stratified by gender, tested the relationship of age, reported health, junk food, participation in leisure PA, TV watching, weight status and socio-economic index for area score (related factors) with the total number of barriers. RESULTS: Girls were more likely to report a greater number of barriers to participation in after-school PA than boys (P < .05). Older age was associated with a higher number of barriers in girls (B(95% CI) = 1.061 (1.032, 1.090)) but not in boys. In both boys and girls, being overweight (boys: very overweight (1.367 (1.081, 1.730)); girls: slightly overweight (1.186 (1.100, 1.278)) or very overweight (1.414 (1.197, 1.667))), compared to students who reported "being about the right weight," was associated with a greater number of barriers. Schoolchildren who reported less than excellent health status perceived a greater number of barriers to after-school PA (girls: good (1.141 (1.060, 1.228)), fair (1.189 (1.070, 1.321)) and poor health (1.329 (1.093, 1.614)); boys: good health (1.166 (1.0728, 1.267))). CONCLUSIONS: There are gender differences in barriers to participation in after-school PA; these should be taken into account when developing programs to increase schoolchildren's after-school PA. SO WHAT: The prevalence of physical inactivity in Australian adolescents is staggering. We observed that girls reported a greater number of barriers to participation in after-school PA than boys; and being overweight and reporting poorer overall health were associated with a greater number of barriers. Affordable, gender- and age-specific after-school PA programs suitable for schoolchildren of all body shapes and sizes and all abilities are needed.

Corticotropin-releasing factor receptor densities vary with photoperiod and sociality.

Life in social groups relies on prosocial behaviors as well as on reduction of antisocial behaviors such as aggression and territoriality. The mechanisms supporting variation in behaviors that give rise to group living (sociality) are largely unknown. Female meadow voles exhibit natural seasonal variation in sociality: females are aggressive and territorial in summer, while in winter they share burrows and nest in mixed-sex groups. This behavioral shift is paralleled in the lab by day length-dependent variation in partner preference formation and social huddling. We exploit natural variation in meadow vole sociality in order to examine changes in neural pathways that coincide with environmental and behavioral variations. Mounting evidence suggests that the corticotropin-releasing factor system, encompassing multiple peptides and two receptor subtypes (CRF1 and CRF2), may play an important role in regulating social behaviors. We report day-length dependent variation in CRF1 and CRF2 receptor binding in female meadow voles, and relate these findings to previously collected oxytocin receptor (OTR) binding data and behavioral data for the same individuals. CRF1 receptor binding was greater in summer-like long day lengths (LD), particularly in the hippocampus, while CRF2 receptor binding was greater in winter-like short day lengths (SD) in the cingulate cortex and hippocampus. OTR varied with day length in the bed nucleus of the stria terminalis, nucleus accumbens, and hippocampus. SD voles huddled more extensively than LD voles, and greater huddling time was associated with more CRF1 receptor binding and less CRF2 receptor binding in subregions of the lateral septum. CRF2 receptor associations with behavior mirrored those of OTR in the lateral septum. Finally, estradiol treatment affected density of CRF receptors in multiple brain regions. CRF receptors and their ligands are promising candidates for enhancing understanding of the regulation of non-sexual social behavior between group living peers.

The effect of exercise interventions on inflammatory markers in major depressive disorder: protocol for a systematic review and meta-analysis.

Background: Depression currently affects 4.4% of the global population, and 93.7% of this population suffer from major depressive disorder (MDD) according to 2017 statistics. MDD patients are more likely to suffer from co-morbidities such as cardiovascular disease and high body mass index (BMI), thus contributing to its large cost to society. Throughout the literature, there are known links between inflammation and MDD. Interestingly, while exercise is considered a promising intervention for MDD, the mechanism(s) of action remain unclear, thereby preventing the creation of optimal, cost-saving, exercise "prescriptions" for those with MDD. Thus, the aim of this review and meta-analysis is to summarize and analyse the current literature exploring how quantified exercise interventions modulate inflammatory molecules in MDD patients. Methods: Electronic databases (APA PsycINFO, and PubMed/MEDLINE (EBSCO interface), EMBASE) will be searched using a detailed search strategy comprised of three search term themes: exercise, depression/MDD, and inflammation/inflammatory molecules. Only quantified exercise interventions performed in adult humans with MDD validated via a recognized diagnostic criterion will be included. Studies should also include a MDD control group and explore changes in inflammatory molecules. Examples of these molecules include: C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-1 beta (IL-1b), tumour necrosis factor-alpha (TNF-a), homocysteine, d-dimer and myeloperoxidase (MPO). After eligible studies are identified, standardized data extraction will be employed and the risk of bias in each study will be appraised using the Cochrane handbook checklists. In the event of two or more homogenous studies exploring exercise effects over a similar time period, raw mean differences or standardized mean differences will be pooled using random effects analysis. This systematic review and meta-analysis will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Dissemination: This systematic review and meta-analysis will be disseminated in peer-reviewed journals. PROSPERO registration: CRD42020186006 (31/08/2020).

Septal oxytocin administration impairs peer affiliation via V1a receptors in female meadow voles.

The peptide hormone oxytocin (OT) plays an important role in social behaviors, including social bond formation. In different contexts, however, OT is also associated with aggression, social selectivity, and reduced affiliation. Female meadow voles form social preferences for familiar same-sex peers under short, winter-like day lengths in the laboratory, and provide a means of studying affiliation outside the context of reproductive pair bonds. Multiple lines of evidence suggest that the actions of OT in the lateral septum (LS) may decrease affiliative behavior, including greater density of OT receptors in the LS of meadow voles that huddle less. We infused OT into the LS of female meadow voles immediately prior to cohabitation with a social partner to determine its effects on partner preference formation. OT prevented the formation of preferences for the partner female. Co-administration of OT with a specific OT receptor antagonist did not reverse the effect, but co-administration of OT with a specific vasopressin 1a receptor (V1aR) antagonist did, indicating that OT in the LS likely acted through V1aRs to decrease partner preference. Receptor autoradiography revealed dense V1aR binding in the LS of female meadow voles. These results suggest that the LS is a brain region that may be responsible for inhibitory effects of OT administration on affiliation, which will be important to consider in therapeutic administrations of OT.