Assignment task: In only one paragraph, write up what was known about capsaicin before they started. Include answers to the following questions
Q1. What did they know about the relationship between capsaicin, a putative capsaicin receptor, and calcium? What is the significance of calcium entry to a cell? If capsaicin opens a channel to let calcium in, how would cells that do not express the capsaicin receptor respond to capsaicin? Would calcium enter cells without the receptor?
Q2. What types of cells were expected to express the capsaicin receptor? Why would these neurons express the capsaicin receptor? Would other cell types have the gene for the capsaicin receptor?
Q3. What was known about the pharmacology of the capsaicin receptor? What are agonists and antagonists? Exogenous means a compound we add to the body (or cells) that is not normally there, like a drug. What was known about the properties of the exogenous compounds resiniferatoxin and capsazepine?
Q4. What was known about the chemical properties of capsaicin? Is it hydrophilic or lipophilic? What is the significance of this for function in a cell? What is the consequence if we eat too much capsaicin?
Q5. What was known about the common motifs of ion channels? What did this predict about a putative capsaicin receptor that is likely to be an ion channel? How would you test this prediction?