Satiation attenuates BOLD activity in brain regions involved in reward and increases activity in dorsolateral prefrontal cortex: an fMRI study in healthy volunteers

BACKGROUND: Neural responses to rewarding food cues are significantly different in the fed vs. fasted (>8 h food-deprived) state. However, the effect of eating to satiety after a shorter (more natural) intermeal interval on neural responses to both rewarding and aversive cues has not been examined. OBJECTIVE: With the use of a novel functional magnetic resonance imaging (fMRI) task, we investigated the effect of satiation on neural responses to both rewarding and aversive food tastes and pictures. DESIGN: Sixteen healthy participants (8 men, 8 women) were scanned on 2 separate test days, before and after eating a meal to satiation or after not eating for 4 h (satiated vs. premeal). fMRI blood oxygen level-dependent (BOLD) signals to the sight and/or taste of the stimuli were recorded. RESULTS: A whole-brain cluster-corrected analysis (P < 0.05) showed that satiation attenuated the BOLD response to both stimulus types in the ventromedial prefrontal cortex (vmPFC), orbitofrontal cortex, nucleus accumbens, hypothalamus, and insula but increased BOLD activity in the dorsolateral prefrontal cortex (dlPFC; local maxima corrected to P ≤ 0.001). A psychophysiological interaction analysis showed that the vmPFC was more highly connected to the dlPFC when individuals were exposed to food stimuli when satiated than when not satiated. CONCLUSIONS: These results suggest that natural satiation attenuates activity in reward-related brain regions and increases activity in the dlPFC, which may reflect a "top down" cognitive influence on satiation. This trial was registered at clinicaltrials.gov as NCT02298049.

Effect of prebiotics on the fecal microbiota of elderly volunteers after dietary supplementation of Bacillus coagulans GBI-30, 6086

In advancing age, gut populations of beneficial microbes, notably Bifidobacterium spp., show a marked decline. This contributes to an environment less capable of maintaining homoeostasis. This in vitro investigation studied the possible synergistic effects of probiotic supplementation in modulating the gut microbiota enabling prebiotic therapy to in elderly persons. Single stage batch culture anaerobic fermenters were used and inoculated with fecal microbiota obtained from volunteers after taking a 28 day treatment of Bacillus coagulans GBI-30, 6086 (GanedenBC30 (BC30)) or a placebo. The response to prebiotic supplements fructooligosaccharides (FOS) and galactooligosaccharides (GOS) in the fermenters was assessed. Bacterial enumeration was carried out using fluorescent in situ hybridisation and organic acids measured by gas chromatography. Baseline populations of Faecalibacterium prausnitzii, Clostridium lituseburense and Bacillus spp. were significantly higher in those having consumed BC30 compared to the placebo. Both prebiotics increased populations of several purportedly beneficial bacterial groups in both sets of volunteers. Samples from volunteers having ingested the BC30 also increased populations of C. lituseburense, Eubacterium rectale and F. prausnitzii more so than in persons who had consumed the placebo, this also resulted in significantly higher concentrations of butyrate, acetate and propionate. This shows that consumption of BC30 and subsequent use of prebiotics resulted in elevated populations of beneficial genres of bacteria as well as organic acid production

Circles of support and accountability: criminal justice volunteers as the 'Deliberative public'

This paper provides a review of the role played by volunteers within one particular offender management and reintegration scheme in the United Kingdom. Circles of Support and Accountability (COSA) draw on the expertise of volunteer members of the public to create supportive monitoring frameworks around sex offenders following their release from prison. The paper presents evidence as to the motivations of these volunteers, and argues that they play a crucial role in the success of the scheme, as they provide an instrumentally-useful form of reintegrative social contact to a socially-excluded offender population, and perform a symbolically important role as representatives of the wider community in taking ownership of offender management practices on behalf of the wider society. This is particularly significant in grounding those processes in the communicative practices of the social sphere, providing powerful reasons for intervention that reinforce the work that COSA do.

Resting-state functional connectivity following a single dose treatment with CB1 neutral antagonist tetrahydrocannabivarin (THCv) in healthy volunteers

BACKGROUND: The cannabinoid cannabinoid type 1 (CB1) neutral antagonist tetrahydrocannabivarin (THCv) has been suggested as a possible treatment for obesity, but without the depressogenic side-effects of inverse antagonists such as Rimonabant. However, how THCv might affect the resting state functional connectivity of the human brain is as yet unknown. METHOD: We examined the effects of a single 10mg oral dose of THCv and placebo in 20 healthy volunteers in a randomized, within-subject, double-blind design. Using resting state functional magnetic resonance imaging and seed-based connectivity analyses, we selected the amygdala, insula, orbitofrontal cortex, and dorsal medial prefrontal cortex (dmPFC) as regions of interest. Mood and subjective experience were also measured before and after drug administration using self-report scales. RESULTS: Our results revealed, as expected, no significant differences in the subjective experience with a single dose of THCv. However, we found reduced resting state functional connectivity between the amygdala seed region and the default mode network and increased resting state functional connectivity between the amygdala seed region and the dorsal anterior cingulate cortex and between the dmPFC seed region and the inferior frontal gyrus/medial frontal gyrus. We also found a positive correlation under placebo for the amygdala-precuneus connectivity with the body mass index, although this correlation was not apparent under THCv. CONCLUSION: Our findings are the first to show that treatment with the CB1 neutral antagonist THCv decreases resting state functional connectivity in the default mode network and increases connectivity in the cognitive control network and dorsal visual stream network. This effect profile suggests possible therapeutic activity of THCv for obesity, where functional connectivity has been found to be altered in these regions.

Exploring the role the brand plays in the choice of charity by UK volunteers

Charities need to understand why volunteers choose one brand rather than another in order to attract more volunteers to their organisation. There has been considerable academic interest in understanding why people volunteer generally. However, this research explores the more specific question of why a volunteer chooses one charity brand rather than another. It builds on previous conceptualisations of volunteering as a consumption decision. Seen through the lens of the individual volunteer, it considers the under-researched area of the decision-making process. The research adopts an interpretivist epistemology and subjectivist ontology. Qualitative data was collected through depth interviews and analysed using both Means-End Chain (MEC) and Framework Analysis methodology. The primary contribution of the research is to theory: understanding the role of brand in the volunteer decision-making process. It identifies two roles for brand. The first is as a specific reason for choice, an ‘attribute’ of the decision. Through MEC, volunteering for a well-known brand connects directly through to a sense of self, both self-respect but also social recognition by others. All four components of the symbolic consumption construct are found in the data: volunteers choose a well-known brand to say something about themselves. The brand brings credibility and reassurance, it reduces the risk and enables the volunteer to meet their need to make a difference and achieve a sense of accomplishment. The second closely related role for brand is within the process of making the volunteering decision. Volunteers built up knowledge about the charity brands from a variety of brand touchpoints, over time. At the point of decision-making that brand knowledge and engagement becomes relevant, enabling some to make an automatic choice despite the significant level of commitment being made. The research identifies four types of decision-making behaviour. The research also makes secondary contributions to MEC methodology and to the non-profit context. It concludes within practical implications for management practice and a rich agenda for future research.

Managing enthusiasm: between ‘extremist’ volunteers and ‘rational’ professional practices in architectural conservation

Geographical research has considered enthusiasm to be a shared passion and a motivator to action. Tensions between enthusiasm as productive, and enthusiasm as negative and prohibitive. Highlights the role of emotion in volunteering with amenity societies. Highlights the presence of enthusiasm in contexts where it is actively denied.