A) dopamine B) noradrenaline C) serotonin D) glycine E) all of the above 29.9. Which of the following are neurotransmitters in the brain? A) dopamine B) noradrenaline C) serotonin D) glycine E) all of the above 29.9. Which of the following are neurotransmitters but not amino acids? A) glutamate B) aspartate C) glycine D) GABA E) none of the above 29.10.