Lab 4 - Paper Discussion I - Prions

Question 1

flehmen

Answer 1

behavior of certain animals that introduces non-volatile chemicals into an organ that functions like the olfactory system; basically lets them smell non-volatile compounds

Question 2

Tg(CerPrP) mice

Answer 2

engineered mice to express the cervid version of the prion protein, PrP

Question 3

immunohistochemistry

Answer 3

IHC - similar to immunofluorescence except that the secondary antibody has an enzyme on it like in ELISA creating a visible reaction product in the tissue sections that can be seen without need for a fluorescence microscope

Question 4

normal prion protein - PrPC

Answer 4

contains several alpha helices

Question 5

misfolded prion protein - PrPSc

Answer 5

contains beta pleated sheets

Question 6

western blotting

Answer 6

procedure used to detect and identify individual polypeptides; determines which proteins are present in or on a particular cell

Question 7

One group received intracerebral exposure. Was that a true control group, used to isolate the effect of a variable, or was the group only used to validate the procedure?

Answer 7

used to validate the procedure and the effectiveness of the inoculum

Question 8

One of the seven aerosol-treated mice did not develop neurological signs of infection. Is there any indication that it was actually infected?

Answer 8

Yes, the mouse tested positive for infection via IHC

Question 9

negative control

Answer 9

oral administration of uninfected brain homogenate

Question 10

Why do farmers tend to have a shorter incubation period?

Answer 10

infection via nasal pathways from kicked up dust and breathing in prions

Question 11

Why was aerosol more effective than intranasal?

Answer 11

smaller particle aggregate in aerosol leads to a higher percentage infection versus intranasal

Question 12

What possible causes could there be for a mouse that tested positive for neurological signs but negative for WB, IHC, and lesions?

Answer 12

some other neurological disorder? old age?

Question 13

Why were mice good test subjects for intranasal/aerosol transmission?

Answer 13

they are obligate nasal breathers

Question 14

variable

Answer 14

independent: method of exposure
dependent: infectivity of PrPCWD

Question 15

What factors do cervids have that mice do not have that make aerosol inoculation more likely?

Answer 15

flehmen

Question 16

Why were only the noses of mice exposed during exposure to prion?

Answer 16

to prevent them from ingesting the prion and being orally infected

Question 17

Why were researchers disappointed in there results?

Answer 17

the infection was only central nervous system, not peripheral… they don’t know how it’s getting to the brain –> most feasible that it’s just going down the back of the throat after entering nasal pathway