Neuroplasticity

Question 1

is the brain a fixed structure

Answer 1

no

Question 2

the brain’s ability to reorganize itself and form new neural connections

Answer 2

neural plasticity

Question 3

what is the extent of plastic changes after injury due to

Answer 3

• spontaneous adaptation and recovery
• rehab process
• enriched environments

Question 4

what is the primary mechanism of neuroplasticity

Answer 4

neuronal sprouting

Question 5

injured neurons reconnect in new ways to remain intact neurons to maximize function of the nervous system

Answer 5

neuronal sprouting

Question 6

how does rehab play a role in neuronal sprouting

Answer 6

• contributes to repair process
• protects intact neurons from degeneration due to disuse
• facilitates rewiring/reorganizing process

Question 7

what are the 2 properties of neuroplasticity and describe them

Answer 7

• habituation: decreased response to repeated benign stimulus; decreased synaptic activity between sensory neurons, interneurons and motor neurons; negative
• reorganization: of neural circuits (cortical maps) resulting in modification of neural responses (changes in behaviors) - more efficient

Question 8

what is neural plasticity dependent on

Answer 8

activity dependent

Question 9

increase or decrease in synaptic connections through pruning and remodeling results in structural changes at the cellular level (increased dendritic arborization, dendritic spine density, number of new synapses, receptor density)

Answer 9

cellular plasticity

Question 10

functional changes at the cellular level for plasticity

Answer 10

• increased/more effective excitatory postsynaptic potentials (long-term potential) and intrinsic excitability via increased levels of brain-derived neurotropic factor (BDNF)

Question 11

describe neural recovery

Answer 11

• Restoration of brain function in tissues that were initially lost due to injury or disease
• Functional recovery

Question 12

describe compensation

Answer 12

• Residual neural tissue takes over the functions of damaged or lost tissue
• Likely produces differences in motor ability/task performance

Question 13

refers to the time during which the wiring of cortical neurons is malleable to an environment stimulus or experience

Answer 13

critical/sensitive periods

Question 14

negative plasticity is fostered by

Answer 14

disuse, practice or attempts at unskilled, non-purposeful activity, reinforcement of negative behaviors, unchallenging tasks, noisy/non-specific sensory input

Question 15

positive plasticity is influenced by

Answer 15

Intense, skilled activity practice; appropriate sensory input; novel, challenging tasks; reinforcement/reward of positive behaviors

Question 16

normal aging is often characterized by physical, behavioral, and environmental changes leading to

Answer 16

negative plasticity

Question 17

what are 4 factors that contribute to age-related functional decline

Answer 17

• reduced brain activity
• weakened neuromodulatory control (decreased neuromodulator)
• noisy processing (degradation of sensory organs = increased processing time)
• negative learning (takes longer to process and integrate new inputs, reduce speed and accuracy)

Question 18

what measures/test can be used to measure neural plastic changes and describe what they look at

Answer 18

• Positron emission tomography (PET) - Images of cerebral cortex activity under certain conditions
• fMRI: Measures changes in blood flow as indirect measure of synaptic activity during select tasks
• transcranial magnetic stimulation - used extracranially to stimulate or inhibit underlying cortex; measures motor evoked potentials

Question 19

what are the 10 principles of neuroplasticity and describe them

Answer 19

• Use it or lose it: must keep neural circuits actively engaged to prevent degradation/atrophy
• Use it and improve it (brain): creative/novel activities promote learning → brain specialization that results in enhancement of function
• Specificity matters: train for skill acquisition not just movement
• Intensity matters: low intensity stimulation = weak synaptic response → must balance high intensity and timing so as not to create further injury
• Repetition matters: large numbers of repetitive motions and progress difficulty of tasks over time
• Timing matters: brain injury evolves and resolves over time - must take advantage of critical periods of recovery
• Salience matters: activities must have meaning to the person - emotion modulates attention and motivation to recover - pts who expect to get better enhance their learning
• Age matters: plasticity occurs more rapidly in young brain, but neural adaptation can occur across lifespan
• Transference matters: plasticity is one area of the brain enhances acquisition in other areas
  Interference matters: plastic changes occurring in a recovering area may interfere with new or existing functions in other parts of the system
• Interference matters: plastic changes occurring in a recovering area may interfere with new or existing functions in other parts of the system

Question 20

What are some of the intervention strategies a PT might use to promote neuroplasticity?

Answer 20

• Intensity of exercise/practice: endurance and aerobic activities are critical for recovery
• Complexity of motor tasks → more novel is better
• Must consider sensory, proprioceptive and kinesthetic inputs
• Plasticity outside of infancy is influences by reward, judgement of error, attention to task
• Sleep patterns - sleep engages strengthening of learning based plastic changes
• Brain derived neurotrophic factor (BDNF) increased with physical exercise
• Cortical stimulation - repetition transmagnetic stimulation (TMS) may enhance learning