Effects of past and present habitat on the gut microbiota of a wild rodent

The response of the gut microbiota to changes in the host environment can be influenced by both the host's past and present habitats. To quantify their contributions for two different life stages, we studied the gut microbiota of wild bank voles (Clethrionomys glareolus) by performing a reciprocal transfer experiment with adults and their newborn offspring between urban and rural forests in a boreal ecosystem. Here, we show that the post-transfer gut microbiota in adults did not shift to resemble the post-transfer gut microbiota of animals 'native' to the present habitat. Instead, their gut microbiota appear to be structured by both their past and present habitat, with some features of the adult gut microbiota still determined by the past living environment (e.g. alpha diversity, compositional turnover). By contrast, we did not find evidence of the maternal past habitat (maternal effects) affecting the post-transfer gut microbiota of the juvenile offspring, and only a weak effect of the present habitat. Our results show that both the contemporary living environment and the past environment of the host organism can structure the gut microbiota communities, especially in adult individuals. These data are relevant for decision-making in the field of conservation and wildlife translocations.

Limb-specific thalamocortical tracts are impaired differently in hemiplegic and diplegic subtypes of cerebral palsy

Thalamocortical pathways are considered crucial in the sensorimotor functioning of children with cerebral palsy (CP). However, previous research has been limited by non-specific tractography seeding and the lack of comparison between different CP subtypes. We compared limb-specific thalamocortical tracts between children with hemiplegic (HP, N = 15) or diplegic (DP, N = 10) CP and typically developed peers (N = 19). The cortical seed-points for the upper and lower extremities were selected (i) manually based on anatomical landmarks or (ii) using functional magnetic resonance imaging (fMRI) activations following proprioceptive-limb stimulation. Correlations were investigated between tract structure (mean diffusivity, MD; fractional anisotropy, FA; apparent fiber density, AFD) and sensorimotor performance (hand skill and postural stability). Compared to controls, our results revealed increased MD in both upper and lower limb thalamocortical tracts in the non-dominant hemisphere in HP and bilaterally in DP subgroup. MD was strongly lateralized in participants with hemiplegia, while AFD seemed lateralized only in controls. fMRI-based tractography results were comparable. The correlation analysis indicated an association between the white matter structure and sensorimotor performance. These findings suggest distinct impairment of functionally relevant thalamocortical pathways in HP and DP subtypes. Thus, the organization of thalamocortical white matter tracts may offer valuable guidance for targeted, life-long rehabilitation in children with CP.

Motives for competitive sports participation in masters track and field athletes: Impact of sociodemographic factors and competitive background

OBJECTIVES

Masters athletes due to their lifelong engagement in sport represent a unique group to study motivation for regular physical activity, but there is less scientific data on the sport motives in masters athletes. Therefore, the aim of this study was to evaluate the association of age, sex, education, nationality, competitive background and training amount with sport motives of masters track and field athletes.

METHODS

811 (254 women) athletes aged 35-89 years participated in European Veterans Athletics Championships in the year of 2000. Sport motives were assessed with a questionnaire and categorized into1) well-being, 2) competitive and performance 3) health and fitness motives.

RESULTS

Men considered health and fitness motives more important than women (p = 0.022). Over 65-year-old athletes considered health and fitness motives more important than the youngest, 35-49-year age group (p<0.001). Education was not associated with sport motives, while motives varied significantly among different nationalities. Athletes from Nordic Countries considered well-being motives more important than Southern Europeans (p<0.001) or Western Europeans (p<0.05). Athletes from Nordic Countries (p = 0.003), Eastern Europe (p<0.001) and Central Europe (p<0.001) found health and fitness motives more meaningful than athletes from the British Isles. Furthermore, athletes with competitive background before the age of 35 and training amount more than 7.5 h a week found competitive and performance motives more important than athletes without a competitive history (p = 0.002).

CONCLUSIONS

These results suggest that age, sex, nationality and former athleticism are associated with sports motives among international level masters track and field athletes. It seems that while for masters athletes with competitive background performance motives dominate, for older adults, particularly for males, health and fitness motives are more important. In addition, when designing the exercise interventions for older adults, different sport motives across countries should be considered.