L2/3 - Methods in modern neuroscience I and II

Question 1

What is an advantage of zebrafish as a model organism?

Answer 1

Zebrafish is transparent early stages so easy to image

Question 2

What are methods to find areas of activity in brain? (3)

Answer 2

-Lesions
-Whole brain imaging techniques (FMRI, enhancer traps)
-Multi-electrode recordings in different brain areas (share electrode, patch clamp)

Question 3

What are the two methods of whole brain imaging currently used? (2)
What do they do? (2)

Answer 3

-FMRI
Shows increase in parts of brain that are active

-Enhancer traps
Green fluorescent protein expressed to show morphology

Question 4

What us the outdated method of whole brain imaging?
What is the problem with it?

Answer 4

Golgi staining

Can kill some cells

Question 5

What issues do while brain imaging techniques have? (2)

Answer 5

-Does not allow for staining of individual neurones

-Cannot combine electrophysiology and morphology assessment for the same cell

Question 6

What are the two types of electrode recording techniques? (2)

Answer 6

-Sharp electrode recordings
-Patch clamp

Question 7

Describe sharp electrode recording?
What does it do?

Answer 7

Sharp/small glass tip
-Inserts into cell body and measures changes in membrane potential

Question 8

What are disadvantages of sharp electrode recordings? (3)

Answer 8

-No solution change inside or outside the cell (some electro-injection is still possible)
-Limited possibility for controlling membrane potential
-Cannot measure single channels

Question 9

How do you carry out the patch clamp technique? (3)

Answer 9

-Use glass electrode filled with electrolyte, similar to intra- or extracellular solution.

-Touch the cell and apply negative pressure.

-Part of the membrane will form tight junction with the electrode, and you will be able to record currents through this patch or can break membrane to record whole cell

Question 10

What are the 4 configurations of patch clamp? (4)
What do they do?

Answer 10

On cell (all start like this)
-Allows you to measure activity of individual channels/APs

Inside out
-Can record individual ion channels, have good control of solution inside cell

Whole cell
-Can apply stronger negative pressure, breaks part of membrane and record current through the rest of the membrane (very difficult)

Outside out
-Can record individual ion channels, have good control of solution outside cell

Question 11

How do you determine morphology and electrophysiology of a cell in one experiment?

Answer 11

Adding fluoresce dye to pipette solution of electrode