Lecture 13: Neuroplasticity

Question 1

what is neuroplasticity

Answer 1

The brain’s ability to modify, change, and adapt throughout life and in response to experience

The connection between neurons can be modified: synaptic plasticity

Question 2

what are the 3 basic aspects of neuroplasticity

Answer 2

Neuroplasticity includes several different processes

It is continually taking place throughout the lifespan

It can be maladaptive in some cases

Question 3

are connections between neurons static or dynamic

Answer 3

dynamic.

there is constant changing based on our experiences

Question 4

neuroplasticity forms the basis of what?

Answer 4

neurorehabilitation

Question 5

what is Homosynaptic Plasticity

Answer 5

Changes in synaptic strength localized to a post-synaptic target neuron stimulated by its own pre-synaptic neuron

Question 6

what is Heterosynaptic plasticity

Answer 6

activity of a neuron leads to changes in the strength of synaptic connections of other neurons

example: Interneurons release other neurotransmitters that act on the synapse

Question 7

what are the Two main types of Short-Term Plasticity

Answer 7

Short-term potentiation

Short-term depression

Question 8

what is Short-term potentiation

Answer 8

Short-term ↑ in synaptic strength

Neurons that fire together, wire together

Question 9

what is Short-term depression

Answer 9

Short-term ↓ in synaptic strength

Neurons that fire out of synch, lose their link

Question 10

what are the two types of Long-Term Plasticity

Answer 10

Long-term potentiation

Long-term depression

Question 11

what is Long-term potentiation

Answer 11

Long-term increase in
synaptic connections

Question 12

what is Long-term depression

Answer 12

Long-term decrease in
synaptic connections

Question 13

what is the Neuroplasticity Time Frame

Answer 13

Short term changes in synaptic strength

• Temporary functional changes from short term potentiation and depression that take seconds

Long term changes in synaptic strength

• More permanent, structural changes caused by long term potentiation and depression that take minutes to hours

Question 14

what are the 4 mechanisms of Long-term potentiation and its result

Answer 14

Ca2+ enters the post-synaptic cell to act as a secondary messenger

Glutamate is released from the presynaptic neuron and binds to AMPA receptors

More AMPA receptors are added

↑ in number, size & length of dendritic spines

Results in strengthening of synaptic transmission (LTP)

Question 15

To change synaptic plasticity on a long-term basis requires which 2 things

Answer 15

Gene transcription

Protein synthesis

Question 16

what are mechanisms for Long-Term Depression

Answer 16

Removal of AMPA receptors from post-synaptic membrane

Can’t continually strengthen synapses – needs to be a mechanism to selectively weaken synapses (synapsing pruning)

Low frequency continuous input (the brain doesn’t think something is important)

LTD and LTP have opposing but complementary functions (they abolish each other)

Question 17

what is the result of Long-Term Depression

Answer 17

Postsynaptic membrane is less likely to be depolarized

Question 18

How do our brains know which synapses to strengthen or weaken?

Answer 18

Repeated, high frequency stimulation of sufficient amplitude→LTP

Repeated, low frequency stimulation while postsynaptic membrane is hyperpolarized or weakly depolarized→LTD

Question 19

what is the Role of Dopamine in Plasticity

Answer 19

Can affect synaptic plasticity by modulating AMPA and NMDA receptors

Question 20

how is CNS injury different from PNS (3 ways)

Answer 20

Neuronal death

Overgrowth of glial cells contribute to glial
scarring

Axonal regeneration severely hindered

Question 21

Recovery after brain injury is primarily due to what

Answer 21

reorganization of function using remaining intact circuits rather than repair of damaged brain tissue

Question 22

what is an Ischemic stroke

Answer 22

Blockage that prevents the brain from getting blood flow

Question 23

what is Penumbra:

Answer 23

Reversibly injured brain tissue around ischemic core

Question 24

what is Synaptogenesis

Answer 24

Formation of new synapses

main type is reactive synaptogenesis

Question 25

what is Reactive synaptogenesis

Answer 25

(collateral sprouting) * Neighbouring axons sprout to innervate synaptic sites previously activated by injured axons

Question 26

what is Neurogenesis

Answer 26

Birth of new neurons

Question 27

what is Cortical Reorganization

Answer 27

Sensory and motor maps undergo constant revision so another part of CNS takes over an area of lost function

Question 28

what are the 4 aspects of Experience-Dependent Plasticity

Answer 28

Early in learning and after brain injury, many regions of the brain are active With repetition, the number of active areas decreases because we get more efficient Cortical reorganization can occur well after injury These changes are consolidated during sleep

Question 29

what is the relationship with performance and brain activity in Experience-Dependent Plasticity

Answer 29

as our performance improves, the amount of brain activity decreased

Question 30

Does Exercise Promote Neuroplasticity?

Answer 30

Executive function is most responsive to aerobic exercise Memory most responsive to resistance training

Question 31

How does Exercise Promote Neuroplasticity? (3 ways)

Answer 31

Increases growth factors Promotes cortical reorganization Increases the complexity and density of dendritic spines

Question 32

what are the 5 Clinical Implications of neuroplasticity

Answer 32

Activities need to be both repetitive and challenging Need to consider treatment dose when prescribing therapy Activities must be meaningful Create an environment that is conducive to plasticity Activity is important

Question 33

why are Repetitive and Challenging Activities important for neuroplasticity

Answer 33

Constraint-Induced Movement Therapy: increased motor map area Performance of skilled motor tasks promotes neuroplasticity

Question 34

why is Treatment Dose important for neuroplasticity

Answer 34

More therapy usually results in better outcomes Timing also matters

Question 35

why are Meaningful Activities important for neuroplasticity

Answer 35

Plays a role in reward, motivation, and reinforcement dopamine release is linked to the meaningfulness of a task

Question 36

why is Environment important for neuroplasticity

Answer 36

Exercise priming (exercise before therapy can decrease GABA (inhibitory) may increase cortical excitability

Question 37

why is Activity is Important for neuroplasticity

Answer 37

Prolonged lack of movement can result in loss of function in undamaged adjacent areas

Question 38

Match the correct statement to the type of short-term plasticity Short-term depression: increase in neurotransmitter Short-term depression: short-term decrease in synaptic strength Short-term potentiation: decrease in the availability of neurotransmitter Short-term potentiation: short-term decrease in synaptic strength

Answer 38

Short-term depression: short-term decrease in synaptic strength

Question 39

Which of the following statements are correct regarding homosynaptic and heterosynaptic plasticity? Interneurons are not involved in homosynaptic plasticity Homosynaptic plasticity is more localized than heterosynaptic plasticity All of the responses listed are correct In homosynaptic plasticity, the postsynaptic neuron is stimulated by its own presynaptic neuron

Answer 39

All of the responses listed are correct

Question 40

When Adria's dog Tui heard the fire alarm go off for the first time which scared her, what likely happened to her synapses within the first few milliseconds or seconds? Neither structural nor functional changes Mostly functional changes Mostly structural changes Structural and functional changes

Answer 40

Mostly functional changes

Question 41

Which of the following responses is true regarding CNS injury in comparison with PNS injury? There is less neuronal death following CNS injury There is glial scarring following PNS injury Axonal regeneration is not possible following CNS injury Axonal regeneration is very limited following CNS injury

Answer 41

Axonal regeneration is very limited following CNS injury