This is a cross-section of a human brain, facing left. The lights are showing you some of the areas in the brain that use the neurotransmitter dopamine. One of these areas is the mesolimbic pathway. Mesolimbic system neurons have their cell bodies in the midbrain and send their axons forward to the limbic system and cortex. At the axon terminal, vesicles containing dopamine fuse with the presynaptic cell membrane, releasing the neurotransmitter into the synaptic cleft.