Module 12

Question 1

4 advantages of electrophysiology

Answer 1

Can measure events on μs timescale
Can measure activity of single ion channel
Spatial resolution can be good
Can tell us how channels work

Question 2

3 types of electrophysiology

Answer 2

Extracellula
Jntracellular
Patch

Question 3

Eg of extracellular

Answer 3

EEG
ECG

Question 4

What are the 3 configurations of patch clamp that all recording of single cells

Answer 4

cell attached,
Outside-out
Inside-out

Question 5

What configuration allows recording of many channels

Answer 5

whole cell
Perforated patch (which could be considered the same thing or diff)

Question 6

How do u make the patch clamp electrode

Answer 6

glass tube put inside heating element
Then each end pulled apart
Make sure to heat the end so the edges are smooth

Question 7

What is added to outside of patch clamp electrode to insulate it

Answer 7

thick resin

Question 8

Approx diameter of patch clamp electrode tip

Answer 8

1 micrometre

Question 9

Micromanipulator function

Answer 9

converts large hand movements to small scale movements

Question 10

What type of microscope most commonly used with patch clamp

Answer 10

flurorecesnce jksdhg microscope

Question 11

How can a micromanipulator be made more specific than a manual one

Answer 11

use one with a hydrolic system

Question 12

What is most expensive piece of equipment in patch clamp rig

Answer 12

patch amplifier
Amplifies the small currents produced by the patch clamp

Question 13

What is AD board

Answer 13

analogue to digital converter

Question 14

How is perforated patch a variation of whole cell recording

Answer 14

Instead of further suction to puncture the memb
Add pore forming antibiotic to pipette
Perforates memb
To form continuous path between pippete electrode thing and the cell

Question 15

In inside out, why does cell need to be pulled out of bath soln briefly

Answer 15

so ends form seal with electrode instead of sealing together

Question 16

Applications of cell attached

Answer 16

record currents of 1 or 2 channels under the electrode
Can see response to cell changes by the channel

Question 17

Applications of whole cell recordi g

Answer 17

record currents through channels across whole cell
Can see response to drugs added from outside into the cell
Can change solutions quickly, good for drug testing where u need to change conc fast

Question 18

Application of inside out recording

Answer 18

can manipulate things on intracellular face
And measure changes in channel

Question 19

Applications of outside out recordings

Answer 19

Can manipulate things on extracellular surface
Can change solutions daily quickly, but whole cell still preffered cuz outside in is hard to set up

Question 20

How can an agonist affect rate constants

Answer 20

agonist binding will increase k+1 (going forward)
And decrease k-1

Question 21

How do we find the rate constants

Answer 21

finding the mean of the closed time and open time

Question 22

What is conductance

Answer 22

ability of channel to move ions through pore
Can measure this to investigate properties of Channel pore

Question 23

How to find conductance

Answer 23

measure current at diff memb potentials

Question 24

what type of cell is two electrode voltage clamp used on

Answer 24

larger cells
usually in Xenopus oocyte experimetns

Question 25

what does each electrode do in a TEVC

Answer 25

a voltage electrode that measures the memb potential and a current electrode that injects current to maintain the clamp A whole cell clamp would use a single electrode to do both of these things

Question 26

what type of test can be combined with patch clamp to find info about expression levels of diff channels

Answer 26

reverse transcriptase PCR

Question 27

when doing patch clamp on tissue slices, why is positive pressure force added to electrode

Answer 27

to get rid of debris and find the cell needed