Chapter 8

Question 1

What is plasticity?

Answer 1

chemical synapses undergo changes that strengthen or weaken transmission

Question 2

Time durations of Short Term vs Long Term?

Answer 2

Short term is minutes max, long term can be years

Question 3

How do the different forms of short-term plasticity differ?

Answer 3

In time and mechanism

Question 4

4 forms of short-term plasticity

Answer 4

facilitation, depression, potentiation, augmentation

Question 5

How long does facilitation last?

Answer 5

Up to tens of milliseconds

Question 6

How long does potentiation last?

Answer 6

seconds to minutes, sometimes passed tetanic stimulation

Question 7

How long does augmentation last?

Answer 7

few seconds

Question 8

Definition of facilitation

Answer 8

rapid increase of synaptic strength due to 2 or more AP invading pre within milliseconds of each other

Question 9

Definition of depression

Answer 9

NT release declines due to sustained release of NT

Question 10

Definition of potentiation and augmentation

Answer 10

Repeated AP in pre causes increased amount of NT released

Question 11

Mechanism of facilitation

Answer 11

Prolonged elevation of pre calcium levels… calcium returns slowly so AP is being reached before it can leave

Question 12

Mechanism of depression

Answer 12

Less NT available overall because time is needed to rebuild NT storage, changing calcium concentrations leads to NT release

Question 13

What two short-term plasticity types work similarly and do what?

Answer 13

potentiation and augmentation both enhance ability of calcium to trigger exocytosis

Question 14

Mechanism of potentiation

Answer 14

potentiation out lasts tetanic stimulation, causing excitability in cell

Question 15

Mechanism of augmentation

Answer 15

reserving calcium to slow response

Question 16

What does Eric Kandel study and where?

Answer 16

He studies LTP at Columbia University using sea slugs

Question 17

What is habituation?

Answer 17

process that causes animals to become less responsive to repeated stimulus

Question 18

What is sensitization?

Answer 18

process that makes animal create an aversive response to usually unharmful stimuli because harmful stimuli is now associated with unharmful, resetting any habituation in expectation of harm

Question 19

What is short term sensitization due to?

Answer 19

a PKA dependent increase in glutamate… over active pka , more calcium, more glutamate

Question 20

What is long term sensitization due to?

Answer 20

genetic changes that causes sustained PKA activity

Question 21

What is long term potetiation?

Answer 21

patterns of synaptic activity that produce long-lasting increases in synaptic strength

Question 22

More synaptic strength leads to what type of changes?

Answer 22

functional changes

Question 23

What is required for LTP information storage?

Answer 23

strong activity in the pre and post

Question 24

Long term potentiation is _______ and _______

Answer 24

specific and associative

Question 25

What is specificity?

Answer 25

LTP only affects the target neuron, not nearby ones

Question 26

What is associativity?

Answer 26

weak stimuli alone doesn't produce LTP, but if weak is paired with strong stimuli of nearby neuron, both undergo LTP strengthening

Question 27

What happens to the mechanism during low freq stimulation in LTP?

Answer 27

NMDA receptor is blocked by magnesium, not triggering LTP

Question 28

What happens to the mechanism during high freq stimulation in LTP?

Answer 28

magnesium is expelled from NMDA, allows calcium to enter post and trigger LTP

Question 29

2 requirements for the NMDA receptor to function, what has to occur?

Answer 29

glutamate must be bound | post cell must be depolarized (low freq doesn't achieve this)

Question 30

What does Ca2+ trigger?

Answer 30

LTP!

Question 31

How do we known Ca2+ triggers LTP?

Answer 31

calcium induces two protein kinases, CaMKII and PKC | calcium is seen at increased levels during LTP

Question 32

How does LTP structurally change the neuron and what does it cause?

Answer 32

new AMPA receptors are created, giving more surface area and increased glutamate sensitivity

Question 33

What mechanism leads up to new AMPA receptors being made?

Answer 33

1. tetanic stim has magnesium removed, calcium in 2. consistent PKA 3. new receptors created and cause structural change

Question 34

What does a tetanic stimulation raise?

Answer 34

raises calcium levels

Question 35

What is Long Term Depression?

Answer 35

selective weakening of sets of neurons

Question 36

How does LTD work?

Answer 36

low freq stim for a long time depresses EPSPs and the post-synaptic neuron loses response

Question 37

Compare and contrast LTD vs LTP

Answer 37

both: require NMDA receptors, require rise of calcium in cell LTD: small slow rise of calcium, loss of AMPA receptors LTP: large fast rise of calcium

Question 38

How does LTD in cerebellar neurons work?

Answer 38

it focuses on two fibers reduces strength of transmission between those fibers associative of both fibers

Question 39

What two fibers are affected in LTD in cerebellar neurons?

Answer 39

climbing fibers & parallel fibers