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 likelyhood of facilitation 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 pre n following a depression?

Answer 12

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

Question 13

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

Answer 13

depression and facilitation

Question 14

What do a lot of short term effects affect?

Answer 14

Calcium

Question 15

Is short term synaptic plasticity specific for neurons?

Answer 15

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

Question 16

Result of post-tetanic potentiation?

Answer 16

A gradual increase in the amplitude of the postsynaptic potential

Question 17

What does post-tetanic potentiation represent?

Answer 17

storage of information about previous activity

Question 18

How long can a post-tetanic potentiation last?

Answer 18

It can lasts minutes but can persist for an hour.

Question 19

What is the hebbian synapse?

Answer 19

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

Question 20

How does a Hebbian synapse come about?

Answer 20

A series of connected neurons undergo repeated coodinated activity

Question 21

What sort of change is the hebbian synapse?

Answer 21

Long term

Question 22

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

Answer 22

Long term depression

Question 23

What does long term potentiation lead to?

Answer 23

Increased activity of a synapse

Question 24

What does long term depression lead to?

Answer 24

results in reduced activity of a synapse

Question 25

What are LTP and LTD the basis of?

Answer 25

memory

Question 26

LTP glutamate example mechanism?

Answer 26

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

Question 27

Which specific molecules are involved in LTP formation?

Answer 27

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