Letters

AMPK is a master regulator of cellular metabolism. Here the authors show that a constitutively active AMPK mutation protects mice fed a high-fat diet from obesity by increasing energy expenditure in subcutaneous white adipocytes, possibly as a result of the emergence of a hitherto-unknown type of adipocyte.

Olfactory food perception is known to extend lifespan in C. elegans. Here the authors demonstrate food-odour-dependent brain-to-gut communication that extends lifespan in worms. Food odour downregulates tir-1 mRNA in AWC neurons, in a manner dependent on the miRNA miR-71, which triggers downstream effects in the gut, due to neuropeptide secretion, that promote proteostasis and longevity.

Neurons and astrocytes cooperate metabolically but differ in key aspects of their metabolism, including the production of mitochondrial reactive oxygen species (ROS). Here, the authors show that mitochondrial ROS produced in astrocytes affect neuronal metabolism and mouse memory and behaviour.

Perineuronal nets (PNNs) are extracellular matrix structures that have been linked to neuronal plasticity in the cortex and hippocampus. Here, the authors report the existence of PNN-like structures in a key region regulating energy homoeostasis, the hypothalamic arcuate nucleus, and show that PNN formation in this area early in life is influenced by the hormone leptin.