Lecture 3.2

Question 1

What is single unit recording, what type of electrode does it use?

Answer 1

Extracellular recording from a single neuron

Uses a metal of glass microelectrode

Question 2

What are some strengths of single unit recording?

Answer 2

Can be used anywhere in the nervous system
Multiple recordings can be made in several sites
Can be readily used in vivo

Question 3

What are some weaknesses of single unit recording?

Answer 3

Does not detect neurons that do not fire action potentials

Does not identify membrane potential changes that cause changes in firing

Question 4

What is intracellular recording and with what type of microelectrode?

Answer 4

IR records membrane potential therefore measuring action potentials, synaptic potentials etc.
The microelectrode is sharp with 0.05-0.5 micron tip inserted into the neuron, made of glass filled with conducting solution

Question 5

What are some strengths for intracellular recording?

Answer 5

allows long term recording of membrane potentials

Question 6

What are some disadvantages of intracellular recording?

Answer 6

Does not allow underlying currents to be measured and does not locate where signals are generated
Large damage to the cell

Question 7

What is the voltage clamp method?

Answer 7

Records membrane potential with one electrode and passes a current with another
Measures current needed to keep membrane potential constant

Question 8

What are some strengths of voltage clamp?

Answer 8

Good time resolution, measure underlying currents

Question 9

What are some weaknesses of voltage clamp?

Answer 9

Only works in large cells as you need two electrodes, does not provide good control of dendrites

Question 10

What is the patch clamp technique and what type of electrode does it use?

Answer 10

2-5 micron tip
Forms a tight seal with membrane called a GigOhm
Can isolate single ion channel in intact cell membrane

Question 11

What is whole cell patch recording?

Answer 11

It makes a large hole in the membrane and brings the inside of the electrode into contact with the cell cytoplasm

Question 12

What are some positives about whole cell recording?

Answer 12

Most popular method for in vitro
low noise
seal to membrane gives stable recording

Question 13

What are some disadvantages to whole cell recording?

Answer 13

Recording duration can be limited to dialyses of the cytoplasm
Needs a clean cell, not good when there are connective tissues
Not good for large networks