human anatomy and physiology question, how do you answer this?

please help i don't know how to answer this.

explain which chemical substance, it's location, and whether it has an inhibitory or excitatory effect for the following: 1. Why do people feel "high" from cocaine? 2. Michael J. Fox suffers from a disease that affects voluntary control of muscles. What causes Parkinson's disease? 3. What blocks the transmission of Substance P? 4. A murder decides to kill his victim using strychnine. How does this physiological result in death? 5. Janine is suffering from delusions. Which neurotransmitter is involved?