Level of life
Cell
The smallest unit that can live on its own. Every living thing is made of one or more cells.
Neuron
A nerve cell that carries electrical and chemical signals. The human brain has about 86 billion of them.Source: NINDSSource: Azevedo et al., 2009
Also called nerve cell.
Structure
How Neuron connects
Neuron is an example of
Neuron makes up
Structure
Brain
The organ that controls thought, movement and many body functions. It holds neurons and other cells in roughly equal numbers.
Neuron is the site of
Process
Action potential
A brief electrical pulse that travels along a neuron as sodium and potassium ions flow through channels.
Neuron is involved in
Process
Synaptic plasticity
Connections between neurons can strengthen with use. Long-term potentiation is a much-studied cellular model of learning and memory.
Studied in
Your progress
Sources & further reading
The explanations on this page are our own summaries of these sources. Follow a link to read the original; if anything here disagrees with it, the original wins. How we choose and check sources.
Brain Basics: The Life and Death of a Neuron (opens the original in a new tab)
National Institute of Neurological Disorders and Stroke. ninds.nih.gov. National Institute of Neurological Disorders and Stroke, NIH.
ReferenceGovernment sourceEducationalEqual numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled-up primate brain (opens the original in a new tab)
Azevedo FA, Carvalho LR, Grinberg LT, et al. (2009). Journal of Comparative Neurology 513:532-541.
Counted about 86 billion neurons and a similar number of non-neuronal cells in adult male brains.
Peer-reviewedPrimary research