At birth, the brain contains its own immune cells, called microglia, that are thought to persist throughout life without being replaced by cells from outside the brain. Studies that trace cell lineage now show that these cells are replaced by circulating immune cells during ageing, revealing a previously unappreciated interaction between the brain and the rest of the body.

In one inbred strain of laboratory mice, late-life treatment with a GLP-1 drug extends lifespan. This effect might be more than just a consequence of calorie restriction.

An analysis of the nutritional content of aquatic invertebrate species suggests that their global production is a rich source of nutrients that are crucial for human health. The work provides a foundation for better recognition of these valuable invertebrate nutrients and incorporate them into conservation, management and policy efforts.

The first record of global methane in the tropics, collected from the summit of the mountain Nevado Huascarán in Peru, fills a crucial gap in historical methane data sets. It improves our understanding of the contribution of tropical sources to the past and current global methane distribution.