Final answer:
The movement of endocytic vesicles from the synapse to the neuron cell body is called retrograde transport, facilitated by dynein motor proteins.
Step-by-step explanation:
The movement of endocytic vesicles formed in the neuron terminals from the synapse to the cell body is said to be in a retrograde direction. This retrograde transport is facilitated by motor proteins, specifically dynein. The ATP-dependent dynein motor, as part of a dynactin complex, powers this retrograde movement, bringing empty vesicles back to the cell body for recycling. This is opposite to the anterograde movement, where kinesin proteins move vesicles from the cell body to the nerve endings, carrying neurotransmitters and other necessary compounds to the synapse for cellular communication.