Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PSYC2020 Q1 > Wk 4 - Neuroplasticity > Flashcards

Wk 4 - Neuroplasticity Flashcards

1
Q

Two critical principles in the maintenance/organisation of neural circuits are…

A

Time-dependence, eg critical/sensitive periods

Experience/use - neurons that fire together wire together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Two major manipulations used historically to impact neural generation
Plus one more recent

A

Deprivation
Enrichment
Exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Deprivation, re neural generation, involves…. (x2 egs)

And leads to… (x2)

A

Rearing animals in the dark, sewing eye shut
Fewer synapses and dendritic spines
Poor depth and pattern perception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Enrichment of environment involves (x1)
And leads to …
With impacts on… (x4)

A

Comparing rats raised in standard – food, water, each other – with those in cage with wheels, ladders etcn
Neural difference in cortex - more dendritic spines and synapses
Vision, sensorimotor function, hippocampus, cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Effects of enrichment on the hippocampus (x2)

Leading to conclusions of (x1)

A

60% increase neurones in the dentate gyrus of the hippocampus, also in olfactory bulbs
Association with exercise and interaction with enriched environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Van Praag et al, 2000, studied the effects of enrichment on neuroplasticity by (x2)
Concluding that… (x1)

A

Looking at hree different levels of environment
Key is number of small red dots appearing = new cells in the dentate gyrus
Runner, esp enriched-runner, environments, = more new neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q 
Voss et al, 2013, furthered understandings of exercise and neuroplasticity through study of rats in... (x4 conditions)
Enabling the (x1) and finding that.. (x1)
A

Control cage, enriched only, running equipment only, and all

Separation of running from enrichment – it’s the exercise that’s driving generation of new neurons in adult rats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Studies on impact of exercise on human neuroplasticity have shown… (x4)

A

Exercise also works for us
Image shows human hippocampus - specific to the dentate gyrus
Study measured blood flow during list learning task – you remember more and more over time
Post-exercise, blood volume goes up during first trial learning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hubel and Wiesel’s research on cats showed the effects of deprivation in study involving… (x7)

A

Looking at ocular dominance columns
Sutured one eye shut in kittens from birth - 2.5 months, and recording the neurons
No cells now activated by contralateral eye - attributed to lack of input,
An example of a critical time period
Then sutured eye shut at 12-38 months
Find similar pattern to normal, but attenuated – few that respond only to ipsi or contra
Shows a sensitive period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Effects of competition in neural development is seen in evidence from vision studies on… (x1)
Showing that… (x1)
For example (describe evidence, x 3)

A

Monocular dominance columns
When you take one system away, others shift and rebalance
Deprivation in one eye during sensitive period = reduced activation of layer IV of corresponding visual cortex,
But activation of other cortex by intact eye is increased
Not just a single process – a shifting and re-balancing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Evidence for the effects of experience on modifying cortical maps is seen in studies involving.. (x3 egs)
Which lead to… (x1 plus eg)
And allows the conclusion that… (x1)

A

Cutting nerves, sewing together fingers of one hand, altering demands on system by increased use
Changed somatosensory mapping, eg relevant part of cortex no longer responds, but starts to respond to adjacent finger
Adult cortex is dynamic - we can enact change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Effects of reorganisation of sensory maps has been found in… (x3)
With effect mediated by… (x1)

A

Primates - sewing fingers together = merging of map boundaries
Musicians - larger somatosensory digit representation
Athletes, other specialised skills
Age - earlier you start, bigger the effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Research into sensory reorganisation in non-elite people involved (x1)
Finding (x1)
Leading to conclusions that (x1)

A

fMRI; trained and untrained sequences
Greater changes in corresponding motor cortex for trained than for untrained after a few weeks
Training can induce rapid changes in organisation that reflect plasticity - still evident 8 weeks on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q 
Knudsen and Brainard looked at effects of experience on topographic sensory maps in study involving... (x1)
Describe study (x5)
A

Raised barn owls with prisms over their eyes - displace visual field
Owls auditory and visual systems integrated for successful hunting - reduces success
Vision mapping shifted in the direction of the prism
Auditory map also shifted in the tectum
Makes sense, because objects need to be heard in the location in space they occupy
Visual mapping shifts, so that success normalises

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Phantom limb phenomena provides evidence for… (x1)

For example, Ramachandran (1993)… (x2)

A

Effects of experience on topographic sensory cortex maps
Studied a patient with an amputated left arm. When parts of his cheek were stroked, the Ps reported sensations in his left hand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Anterograde brain damage is… (x1)

And happens… (x1)

A

From the point of disruption forwards to the synaptic terminals (the distal segment)
Quickly b/c of separation from metabolic centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Retrograde brain damage is.. (x1)
And happens… (x1)
With potential for… (x1)

A

From the point of disruption backwards to the cell body (the proximal segment)
Slow, over days - reduction in size, then death
Increase in production of proteins, but regeneration is not guaranteed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Transneural degeneration is when… (x1)

A

Brain tissue damage spreads to neurones that are linked synaptically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The principles of brain tissue damage are… (x3)

A

A whole bunch of neurons communicate with each other
Then there’s a cut = anterograde degeneration – axon ceases to function, neuron disappears from system
Then two unconnected neurons are subject to retrograde degeneration - whole system is disrupted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Concussion is due to… (x2)

A

Brain keeps travelling, impacts into skull, then goes backwards
Also twists - shearing of axons and bleeding in brain, and adaema (cushions impact area, but can press in on brain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Effects of concussion (x7)

A

Extremely brief loss of consciousness, or may have no loss at all
Temporary confusion
Behavioural, affective and cognitive problems
No evidence of structural (neuronal) damage
Cumulative effect
Internal bleeds
Linear and rotational forces can lead to cell death

22
Q 
Punch-drunk symptoms in boxers are due to... (x1)
Leading to (x3)
A

Concussions
General cognitive deterioration
Scarring after repeated concussions.
Effects are summative

23
Q

Closed head injuries are when… (x1)

Plus five examples

A 
Blow doesn't penetrate skull, but causes:
Contusions
Haematomas
Oedema
Loss of consciousness
Epilepsy
24
Q

Contusions are… (x1)

A

Bruises from brain slamming against skull

25
Q

Haematomas are… (x1)

A

Bleeds due to shearing of blood vessels

26
Q

Oedemas are… (x1)

A

Swelling due to fluid that serves as protective, but damages due to downward pressure on brain

27
Q

Loss of consciousness from closed head injury is due to… (x1)
Which potentially may not happen… (x1)

A

Downward pressure on brain stem, and twisting it in skull

For day or two, then seemingly sudden

28
Q

Penetrating head wounds can cause issues through… (x3)

A

Same five methods as closed, but also:
Infections - non-sterile skull fragments pushed into brain
Scarring = epilepsy

29
Q

Skull fractures may be… (x2)

With the more complex type being… (x1)

A

Linear or depressed

Depressed b/c impacts drives fragments into dura and brain = > infection, and focus for epileptic activity

30
Q

Post-traumatic epilepsy occurs due to… (x1)

And is typically treated with… (x1)

A

Scar tissue - changes in membrane structure and function

Prophylactic anticonvulsants

31
Q

Neuronal biomechanics of TBE (x3)

Leading to consideration for rehab (x1)

A

Anterograde or retrograde degeneration - neurone is not activated by the post-synaptic axon = domino effect of metabolic changes
Neurones not completely ruptured may re-sprout axonal projections = restoration
BUT may form unwanted connections = Behavioural disturbance
Unguided behaviours may lead to inappropriate rewiring, so rehab now starts ASAP

32
Q 
Cardiovascular accidents (strokes) involve... (x1)
Resulting from pathologies of blood vessels, such as (x4)
A

Sudden disruptions to brain’s blood circulation
Lesion of vessel wall
Occlusion of lumen due to thrombus/embolus
Rupture, altered permeability
Increased viscosity or other change of the blood

33
Q

The circle of Willis is… (x1)

Which is pretty poor design because it… (x1)

A

Formed around brain stem by posterior cerebral arteries, middle cerebral arteries, anterior cerebral arteries
Cracks against boney plates upon impact

34
Q

Haemorragic stokes are cause by… (x1)

Due to either (x2)

A

Bleeding inside or around brain tissue when one of these blood vessels bursts (thinner near cortex, more catastrophic if closer to centre)
(Congenital) weakness in wall, or aneurysm

35
Q

Ischaemic strokes are caused by… (x1)

Plus three types

A

Disruption in blood supply due to blockage instead of bursting
Thrombus - clot is stationary
Embolus - clot is on the move due to blood pressure
Arteriosclerosis - substances on artery walls block blood flow

36
Q

Infarcts are… (x1)

A

Areas of dead tissue caused by stroke

37
Q

Penumbras are… (x1)

A

Tissue surrounding infarct that isn’t functioning, but still alive following stroke

38
Q

Mytochondria can also be damagede/lost due to strokes, because… (x2)
And can lead to… (x2)

A

They’re the sight of aerobic metabolism
Hard to overcomes mitochondrial dysfunction - restoration of oxygen doesn’t necessarily do it
Neurotransmitter dysfunction, neurone death

39
Q

The PNS is better than CNS at neural regeneration because… (x3)

A

Schwann cells produce neurotrophic factors to stimulate growth, and cell adhesion molecules on their membranes provide paths for growth
Oligodendrocytes do not have these qualities

40
Q

Three potential outcomes of neural regeneration in the PNS

A

Undamaged Schwann cells = tunnel available for axon regrowth
Small Schwann cell separation = potential for mis-wiring
Large gap = no regrowth - anterograde then retrograde degeneration

41
Q

Colateral sprouting is when… (x1)

And can be harnessed to… (x1)

A

When axon degenerates, axons from neighbouring neurones may grow to synapse at the vacated sites
Promote function

42
Q

CNS reorganisation can occur through… (x2)

A

Strengthening of existing connection due to release from inhibition (by original connections) - insufficient sole explanation for long-term reorganisation
Establishment of new connections by collateral sprouting

43
Q

Neural migration occurs… (x1)
And peaks in the… (x1)
So damage in this period can lead to… (x1)

A

When neurogenesis stops, and neurons move around
Third trimester
Poor functional outcomes - no new neurons to take over

44
Q

Synaptogenesis is… (x1)
And peaks… (x1)
So damage in this period… (x1)

A

Axonal branching and connecting of synapses
During first 18 months
Better outcomes than outside of this time

45
Q

In general, recovery from brain injury is higher among… (x1)

A

Younger patients

46
Q

Intelligence or pre-injury cognitive reserve imapcts rehabilitation from brain injury in that… (x1)
Possibly due to… (x2)

A 
Higher premorbid intelligence = better recovery
Greater plasticity (more education more synapses) 
Generate more strategies to solve problems
47
Q

Sex differences in neural recovery are that… (x1)

Due to… (x1)

A

Females show better functional recovery

Females have less functional lateralisation than males

48
Q

Handedness impacts on neural recovery due to… (x2)

A

Left-handers, less lateralisation of function than right handers
= advantage for recruiting undamaged regions after brain injury

49
Q

Personality impacts neural recovery in that… (x1)

Possibly due to… (x1)

A

Optimistic, extroverted and easy-going individuals tend to have a better prognosis
Greater compliance with rehab program

50
Q

Nervous system damage can be treated through… (x2)

A

Rehabilitative training

Harnessing competition - force/increase use of intact limb while neurones compete for synaptic sites/neurotrophins

PSYC2020 Q1 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions