Final answer:
Motor proteins such as kinesin and dynein mediate axonal transport of vesicles from the neuronal body to the growth cone, with kinesin being responsible for anterograde movement and dynein for retrograde movement. This ATP-driven process ensures the proper delivery of neurotransmitters to synaptic terminals.
Step-by-step explanation:
Axonal transport of vesicles from the neuronal body to the growth cone is mediated by motor proteins such as kinesin. These proteins are essential for the transport of neurotransmitters, which are packaged into vesicles arising from the endomembrane system within neuron cell bodies. The process is powered by ATP hydrolysis performed by the motor proteins. Kinesin specifically mediates the anterograde vesicle movement, which is the transport direction from the cell body towards the nerve endings, while dynein, in association with the dynactin complex, is responsible for the retrograde movement carrying empty vesicles back to the cell body.
These motor proteins navigate along microtubule tracks within the axons, enabling organelles and vesicles to reach the synaptic terminals. At the synaptic terminals, an influx of Ca²+ ions triggers the fusion of neurotransmitter vesicles with the presynaptic membrane, facilitating the release of neurotransmitters into the synaptic cleft through exocytosis. This complex transport mechanism is critical for the proper functioning of neuronal communication.