Signals from gut microorganisms to the brain might be involved in neurodegeneration. It emerges that the gene APOE — variants of which each confer a different risk of Alzheimer’s disease — has a role in modulating this gut–brain communication.

A 319-million-year-old fossil provides the oldest known evidence of preserved vertebrate brain tissue. This specimen offers insights into the brain evolution of ray-finned fishes, the most diverse group of living vertebrates.

A light-activated ‘plasmonic’ catalyst, made from abundant elements, produces as much hydrogen from ammonia as do the most-used heat-activated catalysts based on a rarer element, suggesting a strategy for sustainable chemical production.

The activity of two energy-producing metabolic pathways was recorded in different types of healthy tissue and solid-tumour tissue in mice. Comparisons of these measurements revealed that solid tumours make and use energy more slowly than do most healthy tissues, even though tumours grow and show cell division.