What Is Neuroscience?

Neuroscience is the scientific study of the nervous system — the brain, spinal cord and nerves — and of how its cells and circuits produce everything from a heartbeat to a memory.

Neuroscience is the study of the nervous system: the brain, the spinal cord, and the vast network of nerves that reaches every muscle, organ and patch of skin in the body. It asks how those tissues are built, how they work, how they develop, how they go wrong, and — the deepest question of all — how the activity of billions of cells becomes a thought, a feeling or a decision.

The field is young as a named discipline. The word "neuroscience" came into common use in the early 1960s, when the biologist Francis O. Schmitt founded the Neurosciences Research Program at MIT to bring biologists, chemists, physicists and psychologists together around one subject. The Society for Neuroscience followed in 1969. But the questions are ancient: people have been trying to explain the brain for at least five thousand years.

A meeting point of many sciences

Neuroscience is not one technique or one department. A neuroscientist might be a molecular biologist studying the shape of an ion channel, a physicist building a brain scanner, a psychologist measuring reaction times, a doctor treating epilepsy, or a computer scientist modelling a network of neurons. What unites them is the nervous system as the object of study.

That breadth is the field's strength. A discovery about a single protein — say, the receptor that cannabis acts on — can explain a behaviour, suggest a medicine, and raise a question in philosophy, all at once.

The core idea: cells that signal

The foundation of modern neuroscience is the neuron doctrine: the nervous system is made of separate cells, neurons, that pass signals to one another. Each neuron collects inputs, "decides" whether to fire, and sends a brief electrical pulse — an action potential — down a long fibre called an axon. At the end, it releases chemical messengers across a tiny gap, the synapse, to influence the next cell.

Everything else — senses, movement, memory, mood — is built from patterns of this signalling across enormous networks. The human brain holds roughly 86 billion neurons and a comparable number of supporting glial cells.

Why it matters

Brain and nervous-system disorders — from stroke and dementia to depression and chronic pain — are among the largest causes of illness and disability in the world. Understanding the healthy brain is the route to treating the sick one. And neuroscience increasingly shapes technology too: artificial neural networks, brain-computer interfaces and brain-inspired chips all borrow from what we know of real neurons.