TIN: Week 2

Question 1

What is electrophysiology?

Answer 1

The study of electrical properties of cells

Question 2

What is the resting membrane potential?

Answer 2

voltage difference across the membrane when at rest

Question 3

What is the resting membrane potential of a neuron?

Answer 3

-70mV

Question 4

What is the concentration gradient?

Answer 4

This occurs when the concentration of positive or negative ions is higher in one are than another.

Each molecule has it’s own concentration gradient.

Question 5

What is depolarization?

Answer 5

A change in a neurons membrane potential that makes it more positive.

Question 6

What is hyperpolarization?

Answer 6

A change in the neurons membrane potential that makes it more negative.

Question 7

Who discovered that the nervous system uses electrical activity to perform functions?

Answer 7

Luigi Galvani in 1790

Question 8

What are ionotropic receptors?

Answer 8

transmembrane proteins that form a channel allowing ions to travel in or out of a cell. These channels are opened when the receptor binds a ligand, like a neurotransmitter.

Question 9

What are Voltage-Gated Ion Channels?

Answer 9

transmembrane proteins that form ion channels whose opening and closing is regulated by the membrane potential near the channel.

Question 10

What is an action potential?

Answer 10

The process by which neurons send signals down the axon

Question 11

What are post synaptic potentials?

Answer 11

small, variable changes in membrane potential that range from 1 - 40mV

Question 12

How are EPSPs generated?

Answer 12

by activation of ion channels that depolarise the neuron

Question 13

How are IPSP (inhibitory postsynaptic potentials) generated?

Answer 13

By activation of ion channels that hyperpolarise the neuron

Question 14

Which electrolytes do Action Potentials require

Answer 14

Voltage-gated sodium and voltage-gated potassium
Both are closed at resting
A depolarization results in the opening of sodium channels
At the peak, Na+ channels close & K+ channels open

Question 15

What is Extracellular Recording (ER)?

Answer 15

Electrode is outside, but close to neuron. They only pick up field potentials and low frequency filtered action potentials.
It’s not possible to record Vm rest or post-synaptic potentials.

1) Field potentials
2) Whole nerve activity
3) Multi-unit activity
4) Single-unit activity
5) Multi-electrode arrays (MEA’s)

Question 16

What is field potential?

Answer 16

electrical potential in extracellular space around neurons

Question 17

What are the 2 Types of Sharp Electrodes (which are Intracellular recordings)?

Answer 17

1) Current Clamp- inject current, record voltage

2) Voltage Clamp - apply voltage to generate current

Question 18

What is voltage?

Answer 18

The potential difference in charge between 2 points.
Cause electrons to move in same direction (rather than random)
Pressure inside vs. outside.

Question 19

What is current?

Answer 19

Rate at which an electric charge is flowing

Question 20

What imaging methods have the highest temporal resolution?

Answer 20

EEG & MEG

Question 21

Whats the only electrophysiological method used in humans?

Answer 21

Extracellular recording