In the last 15 years, advances in molecular and cell biology, genetics, electrophysiological recording techniques and imaging methods for looking at both cells and the whole brain have led to enormous progress in our understanding of how different components of the brain work. However, the nervous system is so complicated that we still lack important information about how the brain develops, how it processes information, and how it goes wrong in neurological and psychiatric diseases. Even the most common brain diseases still lack adequate treatments.

The brain and spinal cord contain large numbers of two cell types: nerve cells (neurons) which process information and glial cells which help to control brain development, speed the movement of electrical signals along neurons, and regulate information flow at the junctions between neurons (synapses). Some of the challenges facing neuroscientists who study normal aspects of brain function are understanding how this cellular system processes information from the eyes or ears, generates commands to the muscles that we use to walk or to talk, enables us to plan for the future, allows us to fall in love, and generates consciousness.

Malfunctions in cells in the brain result in serious clinical disorders and these are also the subject of much research. For example, our current knowledge indicates that epilepsy is caused by over-excitation of neurons, depression is caused by altered levels of amine neurotransmitters in the brain, and cancer may be caused by excessive growth of some glial cells. The mental and physical disabilities associated with stroke, spinal cord injury and cerebral palsy are caused by the release of the neurotransmitter glutamate, which damages neurons and glial cells.