As our understanding of the processes that underlie brain damage progresses, it becomes possible to use small-molecule drugs, such as antibiotics and anti-tumor drugs, to alter these processes.

Chemical reactions within brain cells translate the neurotransmitter message for the neuron.

Brain injury is all too common, but treatments are being improved constantly. Those who survive a brain injury face a lifetime of disability, with economic costs approaching $60 billion annually.

Once the neurons reach their final location, they must make the proper connections so that a particular function, such as vision or hearing, can emerge.

How exactly are memories stored in brain cells? After years of study, much evidence supports the idea that memory involves a persistent change in synapses, the connections between neurons.

Studies of the body’s own pain-control system demonstrated the existence of naturally occurring opioids — the endorphins.

HIV attacks the immune system’s cells that help protect the body from infection and can also lead to severe neurological disorders.

Hormones are important messages both within the brain and between the brain and the body.

A stressful situation activates three major communication systems in the brain, all of which regulate bodily functions.

Optical imaging relies on shining weak lasers through the skull to visualize brain activity. These techniques are inexpensive and relatively portable. They are also silent and safe: Because only extremely weak lasers are used, these methods can be used to study everyone, even infants.