Neurotransmitter: A chemical substance released by a neuron into the synapse that transmits signals to other neurons. Example: Serotonin is a neurotransmitter involved in regulating mood.
Receptor: Specialized proteins located on the surface of neurons that receive neurotransmitters, allowing them to transmit their signal. Example: Dopamine receptors bind dopamine molecules in order for them to have an effect.
Synaptic Vesicles: Small sacs within the presynaptic neuron that store and release neurotransmitters into the synapse. Example: Synaptic vesicles contain dopamine molecules waiting to be released during neural firing.