Axonal transport

Dynein, a motor protein responsible for retrograde axonal transport, carries vesicles and other cellular products toward the cell bodies of neurons. Its light chains bind the cargo, and its globular head regions bind the microtubule, "inching" along it.

Axonal transport, also called axoplasmic transport or axoplasmic flow, is the cellular process responsible for moving lipids, synaptic vesicles, proteins, mitochondria and other organelles to and from a neuron's cell body, through the cytoplasm of its axon called the axoplasm. Since some axons are on the order of meters long, neurons cannot rely on diffusion to carry products of the nucleus and organelles to the ends of their axons. Axonal transport is also responsible for moving molecules destined for degradation from the axon back to the cell body, where they are broken down by lysosomes.

Movement toward the cell body is called retrograde transport and movement toward the synapse is called anterograde transport.