Paper 2: TRPV1 Channel

Question 1

Where do vertebrates detect nociceptive (painful) stimuli?

Answer 1

through specialized afferent neurons that enter the spinal cord and synapse within grey matter of dorsal horn

Question 2

Are nociceptive neurons myelinated?

Answer 2

no

Question 3

What parts of the DRG cells did they use to begin their experiments? Why?

Answer 3

cell body – contains nucleus, where mRNA is made

Question 4

What technique did researchers use to find genes linked to capsaicin sensitivity?

Answer 4

expression screen

Question 5

What is necessity?

Answer 5

experiments must show that in the absence of the molecule (ie. after it is removed by some method), the function no longer occurs

Question 6

What is sufficiency?

Answer 6

experiments must show that adding the molecule to another location or system or time is enough to confer the same function to the new system

Question 7

What is the right time, right place criteria?

Answer 7

experiments must show that the molecule is present in the appropriate tissue, during the appropriate time period when the function is actually being carried out

Question 8

What are the three criteria to determine whether a given molecule is important for a developmental event?

Answer 8

• necessity
• sufficiency
• right time, right place

Question 9

What is an agonist?

Answer 9

non-endogenous chemical that can activate an ion channel or cellular receptor

ie. capsaicin, resiniferatoxin

Question 10

What is an antagonist?

Answer 10

non-endogenous chemical that can block or prevent activation of an ion channel or cellular receptor

ie. capsazepine