Physiology

The bird retina is one of the most energetically expensive tissues in the animal kingdom, yet it doesn’t use the energy advantage of oxygen. New research finally explains how this is possible.

A healthy brain maintains a harmony of neurons that excite or inhibit other neurons, but the lines between different types of cells are blurrier than researchers once thought.

The effects of insufficient water are felt by every cell in the body, but it’s the brain that manifests our experience of thirst.

Studies of neural metabolism reveal our brain’s effort to keep us alive and the evolutionary constraints that sculpted our most complex organ.

Slight changes in the number, shape, efficiency and interconnectedness of organelles in the cells of flight muscles provide extra energy for birds’ continent-spanning feats.

A popular hypothesis for how the brain clears molecular waste, which may help explain why sleep feels refreshing, is a subject of debate.

The discovery that other vertebrates have healthy, microbial brains is fueling the still controversial possibility that we might have them as well.

Like a highway system, the vagus nerve branches profusely from your brain through your organs to marshal bodily functions, including aspects of mind such as mood, pleasure and fear.

The evolutionarily ancient part of the brain that controls breathing and heart rate also regulates the immune system — a discovery about the brain-body axis made by experts on taste.