Intrinsic functional brain connectivity changes following aerobic exercise, computerized cognitive training, and their combination in physically inactive healthy late-middle-aged adults: the Projecte Moviment

Lifestyle interventions have positive neuroprotective effects in aging. However, there are still open questions about how changes in resting-state functional connectivity (rsFC) contribute to cognitive improvements. The Projecte Moviment is a 12-week randomized controlled trial of a multimodal data acquisition protocol that investigated the effects of aerobic exercise (AE), computerized cognitive training (CCT), and their combination (COMB). An initial list of 109 participants was recruited from which a total of 82 participants (62% female; age = 58.38 ± 5.47) finished the intervention with a level of adherence > 80%. Only in the COMB group, we revealed an extended network of 33 connections that involved an increased and decreased rsFC within and between the aDMN/pDMN and a reduced rsFC between the bilateral supplementary motor areas and the right thalamus. No global and especially local rsFC changes due to any intervention mediated the cognitive benefits detected in the AE and COMB groups. Projecte Moviment provides evidence of the clinical relevance of lifestyle interventions and the potential benefits when combining them.

Early life factors and hippocampal functional connectivity in children with overweight/obesity

OBJECTIVE

We investigated the association of anthropometric neonatal data (birth length and birth weight) and breastfeeding practices (exclusive and any breastfeeding) with hippocampal functional connectivity and its academic implication in children with overweight/obesity.

METHODS

Ninety six children with overweight/obesity aged 8-11 years (10.01 ± 1.14), from the ActiveBrains project were included in this cross-sectional study. Anthropometric neonatal data were collected from birth records, whereas breastfeeding practices were reported by parents. A 3.0 Tesla Siemens Magnetom Tim Trio system was used to acquire T1-weighted and resting-state functional magnetic resonance images. Academic performance was assessed by the Woodcock-Muñoz standardized test. Hippocampal seed-based methods with post-hoc regression analyses were performed. Analyses were considered significant when surpassing Family-Wise Error corrections.

RESULTS

Birth weight showed a positive association with the connectivity between the hippocampus and the pre- and postcentral gyri, and the cerebellum. In addition, breastfeeding was negatively associated with the connectivity between the hippocampus and the primary motor cortex and the angular gyrus. Any breastfeeding, in turn, showed a positive association with the connectivity between the hippocampus and the middle temporal gyrus. None of the connectivity outcomes related to early life factors was coupled with better academic abilities (all p > 0.05).

CONCLUSIONS

Our findings suggest that birth weight at birth and breastfeeding are associated with hippocampal connectivity in children with overweight/obesity. Despite this, how the results relate to academic performance remains a matter of speculation. Our findings suggest that clinicians should recognize the importance early life factors for potentially avoiding consequences on offspring's brain development.

Episodic Memory in Older Adults Without Dementia: A Meta-Analysis of Aerobic Exercise Interventions

The effect of aerobic exercise interventions on episodic memory performance among older adults without dementia remains a matter of intense debate. Prior meta-analyses examining this association have reported minimal improvements in episodic memory performance following exercise training but have also been plagued by several limitations, including restrictive inclusion criteria, combined sample populations, and infrequent examination of the effect of exercise parameters (e.g., volume). To address these gaps, we conducted a meta-analysis of randomized controlled trials (RCTs) to determine if aerobic exercise interventions influence episodic memory performance in older adults without dementia and to examine potential moderators of these effects (e.g., sample and intervention characteristics). Included studies met the following criteria: (1)Studies of adults (M≥55 years) with normal cognition, subjective cognitive decline, or mild cognitive impairment; (2)Aerobic exercise RCTs; and (3)Assessment of episodic memory. Intervention effects were represented by Hedges’ g and combined into pooled effect sizes using random- and mixed-effects models. Thirty-three studies met inclusion criteria, representing data from 2,488 participants. The primary analysis yielded a significant positive effect of aerobic exercise on episodic memory (Hedges’ g[CI]=0.28[0.10-0.47]; p=0.003). Mixed-effects analyses demonstrated a positive effect on episodic memory among studies with a high percentage of females (>66%), participants with normal cognition, studies reporting intensity, studies with a no-contact or nonaerobic physical activity control group, and studies prescribing 2,100–3,900 total minutes of activity (range 540–8,190 minutes). These results suggest that aerobic exercise may act as an accessible, non-pharmaceutical intervention to improve episodic memory in late adulthood before changes in cognition are detected.

Estimating the financial costs associated with a phase III, multi-site exercise intervention trial: Investigating Gains in Neurocognition in an Intervention Trial of Exercise (IGNITE)

INTRODUCTION

Supervised exercise interventions are expensive and time intensive. However, there are financial costs to consider in addition to the intervention itself, namely: advertising and recruitment, outcome assessments, and other trial-related costs.

OBJECTIVES

In this analysis, we examine the financial costs associated with the administration of Investigating Gains in Neurocognition in an Intervention Trial of Exercise (IGNITE) to quantify the costs associated with large exercise intervention trials and to provide future investigators with financial estimates if they wish to pursue studies of a similar design.

METHODS

Cost per randomized participant were calculated in four areas: (1) advertising and recruitment, (2) outcome assessments, (3) delivery of the intervention, and (4) other trial-related expenses. Overall trial costs associated with data analysis, faculty salaries, and indirect costs were estimated as well.

RESULTS

The total cost per randomized participant was estimated to be $16,494. Outcome assessments accounted for the highest proportion of per-participant (75%) and total trial (38%) costs. Neuroimaging assessments (MRI & PET) cost $8247 per randomized participant, accounting for two-thirds (67%) of outcome assessment costs and half (50%) of per-participant costs.

CONCLUSION

Large clinical trials of exercise are expensive (~$21 million), particularly when administering several visits to assess study aims. Outcome assessments, specifically those involving neuroimaging, accounted for a significant proportion of total costs in this analysis. Future investigators must budget accordingly if they wish to conduct a comprehensive, multi-site exercise intervention trial that examines numerous physiological and psychological outcomes.

Structural comparison of the Pichia pastoris alcohol oxidase genes

In methylotrophic yeasts, alcohol oxidase is the first enzyme in the methanol-utilization pathway. The genome of one such yeast, Pichia pastoris, contains two alcohol oxidase genes, AOX1 and AOX2. Sequence analysis indicated that each gene encodes a similar protein of 663 amino acids. The protein-coding regions of the genes were 92% and 97% homologous at the nucleotide and predicted amino acid sequence levels, respectively. In contrast to homology observed within the protein-coding portions of the AOX genes, no homology was found in either the 5' or 3' non-coding regions. Although alcohol oxidase is found in peroxisomes of P. pastoris, the AOX amino acid sequences did not contain a peptide sequence similar to the peroxisomal transport sequence found at the C-terminus of some peroxisomally located proteins in higher eukaryotes.