neurite

A neurite is a general term for any projection that extends from a neuron. It includes axons and dendrites, and is often used in developmental contexts when the specific identity of the projection has not yet been determined. The term reflects early neuroanatomical usage describing growing processes from nerve cells.

During development, neurites extend from the cell body to explore their environment. A growth cone at the tip, composed of actin-rich filopodia and a veil-like lamellipodium, advances the process. Growth is guided by a combination of chemical cues, cell–cell interactions, and extracellular matrix. Guidance cues include families such as netrins, semaphorins, slits, and ephrins, which can attract or repel growth. The cytoskeleton, including microtubules and actin filaments, is dynamically reorganized during extension and turning. Neurite outgrowth assays in culture are commonly used to study the factors influencing neural connectivity and regeneration.

In mature neurons, neurites differentiate into the axon and dendrites that form the neural circuitry. Axons typically transmit signals away from the cell body; dendrites receive inputs. Neurites can retract or prune during development or in response to injury, and regenerative sprouting may occur after damage. The term remains a useful descriptor in neurobiology for early-stage projections and for describing processes of growth and remodeling of neuronal morphology.