| Answer | Crossword Clue |
|---|---|
| ATP | Chem. neurotransmitter |
| SEROTONIN | Certain neurotransmitter |
| DOPAMINE | Essential neurotransmitter |
| HISTAMINE | Sleep-regulating neurotransmitter |
| DOPAMINE | Neurotransmitter of note |
| DOPA | Neurotransmitter amino acid |
| DOPAMINE | Pleasure-associated neurotransmitter |
| SEROTONIN | Neurotransmitter associated with sleep |
