Neuronal signalling 6 (3rd lecture)

Question 1

Can neurons have different axons that have excitatory and inhibitory effects?

Answer 1

Ye

Question 2

How are v complex circuits formed in the nervous system?

Answer 2

Neurons can have thousands of inputs, and themselves give inputs to thousands of other cells/neurons

Question 3

Two main types of synaptic modulation?

Answer 3

Simple/short term
Complex/long term

Question 4

Short term ways of modulating a synapse?

Answer 4

Facilitation, depression and temporary potentiation

Question 5

Long term mechanisms of synaptic modulation?

Answer 5

Long term potentiation and long term depression

Question 6

What is facilitation?

Answer 6

Two or more APs reach the presynaptic terminals in a short period of time, leading to more NT released per AP

Question 7

Postsynaptic effect of facilitation?

Answer 7

Postsynaptic change is stronger–> increased postsynaptic response

Question 8

How does a postsynaptic response become stronger?

Answer 8

A larger change in depolarisaiton

Question 9

Relationship between amount of differentiation and interval between stimuli?

Answer 9

Larger interval = less likely facilitation is to occur

Question 10

What is a tetanic train?

Answer 10

A rapid succession of action potentials

Question 11

What is the response to a tetanic train?

Answer 11

Depression, NT deletion, decreased NT release

Question 12

What is the effect to a synapse following a depression?

Answer 12

Depression causes change in calcium dependent processes
Synaptic vesicles available per incoming action potential increase.

Question 13

What is a post-tetanic potentiation?

Answer 13

Larger effect occurring after a tetanic train

Question 14

Two short term ways to change the behaviour of a postsynaptic cell of a synapse?

Answer 14

depression and facilitation

Question 15

What do a lot of short term effects affect?

Answer 15

Calcium

Question 16

Is short term synaptic plasticity specific for neurons?

Answer 16

No it is specific for synapses–> same neuron can have multiple synapses that have diff types of synaptic plasticity

Question 17

What is post-tetanic potentiation?

Answer 17

A high rate of stimulation of the presynaptic neuron
A gradual increase in the amplitude of the postsynaptic potential

Question 18

What does post-tetanic potentiation represent?

Answer 18

storage of information about previous activity

Question 19

How long can a post-tetanic potentiation last?

Answer 19

It can lasts minutes but can persist for an hour.

Question 20

What is the hebbian synapse?

Answer 20

Coordinated inputs into a single cell will favour one pathway into that cell
I.e. pathway becomes “remembered”

Question 21

How does a Hebbian synapse come about?

Answer 21

a form of co-ordinated activity for a series of neurones connected together that would strengthen specific pathways

Question 22

What sort of change is the hebbian synapse?

Answer 22

Long term

Question 23

Which long term synaptic effect leads to larger changes in calcium?

Answer 23

Long term depression

Question 24

What does long term potentiation lead to?

Answer 24

Increased activity of a synapse

Question 25

What does long term depression lead to?

Answer 25

results in reduced activity of a synapse

Question 26

What are LTP and LTD the basis of?

Answer 26

memory

Question 27

Long term glutamate example mechanism?

Answer 27

NMDA receptors which usually arent used (AMPA are used instead) are now used

Question 28

Which specific molecules are involved in LTP formation?

Answer 28

NMDA, Ca/calmodulin dependent protein kinases and changes in protein synthesis