Where does neurotransmitter synthesis primarily occur?

Neurotransmitter synthesis primarily occurs in the soma and terminals of neurons. In the soma, which contains the cell's nucleus and most organelles, larger neuropeptides are synthesized in the rough endoplasmic reticulum and are then transported to the axon terminals. Smaller neurotransmitters, such as amino acids and monoamines, can also be synthesized in the terminals themselves.

This dual site of synthesis is crucial for efficient neurotransmitter production and release, as it allows the neuron to produce the necessary molecules close to where they will be released. In contrast, dendrites primarily receive signals from other neurons rather than synthesize neurotransmitters, while synaptic vesicles serve primarily as storage containers for the neurotransmitters rather than being sites of synthesis. Therefore, the correct answer reflects the combined roles of the soma and terminals in the production of neurotransmitters.