Subcortical Connections to Human Amygdala and Changes following Destruction of the Visual Cortex

1. Download : Download high-res image (231KB)
2. Download : Download full-size image

Highlights? Anatomical connections compose a subcortical pathway to the human amygdala ? Destruction of the visual cortex induces anatomical changes along this pathway ? Plasticity in the subcortical pathway is limited to the damaged hemisphere     

Immune Modulation by Different Types of β2→1-Fructans Is Toll-Like Receptor Dependent

Introduction

β2→1-fructans are dietary fibers. Main objectives of this study were 1) to demonstrate direct signalling of β2→1-fructans on immune cells, 2) to study whether this is mediated by the pattern recognition receptors Toll-like receptors (TLRs) and nucleotide-binding oligomerisation domain-containing proteins (NODs), and 3) to relate the observed effects to the chain length differences in β2→1-fructans.

Methods

Four different β2→1-fructan formulations were characterised for their chain length profile. Human peripheral blood mononuclear cells (PBMCs) were stimulated in vitro with β2→1-fructans, and production of IL-1Ra, IL-1β, IL-6, IL-10, IL-12p70, and TNF-α was analysed. Reporter cells for TLRs and NODs were incubated with β2→1-fructans and analysed for NF-κB/AP-1 activation.

Results

Cytokine production in human PBMCs was dose- and chain length-dependent. Strikingly, short chain enriched β2→1-fructans induced a regulatory cytokine balance compared to long chain enriched β2→1-fructans as measured by IL-10/IL-12 ratios. Activation of reporter cells showed that signalling was highly dependent on TLRs and their adapter, myeloid differentiation primary response protein 88 (MyD88). In human embryonic kidney reporter cells, TLR2 was prominently activated, while TLR4, 5, 7, 8, and NOD2 were mildly activated.

Conclusions

β2→1-fructans possess direct signalling capacity on human immune cells. By activating primarily TLR2, and to a lesser extent TLR4, 5, 7, 8, and NOD2, β2→1-fructan stimulation results in NF-κB/AP-1 activation. Chain length of β2→1-fructans is important for the induced activation pattern and IL-10/IL-12 ratios.     

Refining the role of phenology in regulating gross ecosystem productivity across European peatlands

The role of plant phenology as a regulator for gross ecosystem productivity (GEP) in peatlands is empirically not well constrained. This is because proxies to track vegetation development with daily coverage at the ecosystem scale have only recently become available and the lack of such data has hampered the disentangling of biotic and abiotic effects. This study aimed at unraveling the mechanisms that regulate the seasonal variation in GEP across a network of eight European peatlands. Therefore, we described phenology with canopy greenness derived from digital repeat photography and disentangled the effects of radiation, temperature and phenology on GEP with commonality analysis and structural equation modeling. The resulting relational network could not only delineate direct effects but also accounted for possible effect combinations such as interdependencies (mediation) and interactions (moderation). We found that peatland GEP was controlled by the same mechanisms across all sites: phenology constituted a key predictor for the seasonal variation in GEP and further acted as a distinct mediator for temperature and radiation effects on GEP. In particular, the effect of air temperature on GEP was fully mediated through phenology, implying that direct temperature effects representing the thermoregulation of photosynthesis were negligible. The tight coupling between temperature, phenology and GEP applied especially to high latitude and high altitude peatlands and during phenological transition phases. Our study highlights the importance of phenological effects when evaluating the future response of peatland GEP to climate change. Climate change will affect peatland GEP especially through changing temperature patterns during plant phenologically sensitive phases in high latitude and high altitude regions.