Plasticity, Recovery, and Rehabilitation of the Adult Brain Flashcards Preview

PSYCO 377 > Plasticity, Recovery, and Rehabilitation of the Adult Brain > Flashcards

Flashcards in Plasticity, Recovery, and Rehabilitation of the Adult Brain Deck (25):
1

What can neural plasticity be studied through?

-Observable behaviour
-Cerebral maps
-Synaptic organization
-Physiological organization
-Molecular structure
-Mitosis

2

What happens in the prism adaptation? What does this tell us?

-Subjects fitted with prisms can adapt to the shifted visual world
-Neural changes occur in the premotor cortex and visual cortex
-Changes disappear after prism removal
-Inferring plasticity from observable behaviour

3

What is the evidence for plasticity in cortical maps?

-Memory and sensory maps can be altered by experience
-Evidenced by changes in the motor cortex of monkeys after making digit movements
-Musicians show an increase in scale representation
-Blind individuals show an increase in auditory area
-Alteration of the somatosensory cortex with changes in afferent input (cutting the afferent nerve of one or more digits)
-Focal hand dystonia (loss of motor control in a digit after making repetitive synchronous movements)
-Reorganization of somatosensory maps after amputation

4

What is the evidence for plasticity in synaptic organization?

-Computational Challenge
-Cells with more challenging tasks to complete are more complex
-Individual difference in cell complexity based on life experiences (e.g., typist - more complex cells in the finger region)

5

What is the evidence for plasticity in physiological organization?

-Long-term potentiation
-Enhanced synaptic transmission after electrical stimulation of a cell
-Leads to changes in dendritic length and spine density
-Model of how learning occurs

6

What is the evidence for plasticity in molecular structures?

-Gene-chip arrays (allows researchers to see what genes are affected by certain experiences)

7

What evidence does mitotic activity provide for plasticity?

-Adult brain can manufacture new neurons
-Olfactory bulb (stem cells in the lateral ventricles generate new olfactory bulb cells through mitosis)
-Hippocampus (new cells develop from the granule-cell layer and the hilus)
-Survival of neurons are affected by many factors

8

What is the downside of brain plasticity?

-Exposure to drugs produces alterations in dendritic length and spine density (addicts and prefrontal morphology)

9

What are the environment and drug interactions in experience dependent changes?

-Stimulant drugs block the dendritic changes seen after exposure to a complex environment
-Complex environments change the response to drugs
-Stress (changes dendrite morphology and neurogenesis; interactions with experience-dependent changes in the brain)

10

Can plasticity support functional recovery after injury?

-More so compensation compared to recovery. Do not recover missing brain areas (e.g., three-legged cats compensate for missing leg)

11

What is ischemia? What happens during ischemia?

-Happens with brain injury
-Loss of blood supply to an area of the cortex
-In the first seconds changes in pH balance and in the cell membrane occur
-Massive release of glutamate
-Open Ca+ channels
-mRNA is stimulated; protein production is altered
-Tissue becomes inflamed and swollen

12

What is diaschisis?

-Results from ischemia
-Loss of function of an area separate from where the injury occurred (connected by neurons)
-Leads to changes in the localized tissue and surrounding tissue
-Changes in cell metabolism may persist for days
-Can be treated with anti-inflammatory drugs or neuroprotectants

13

Which patients show the most recovery from aphasia?

-Head injury patients
-Deficits are least severe in anomic patients; most severe in global aphasics
-Progress to other stages in recovery, but often stop in anomic stage (difficulty naming objects)

14

What are some examples of the types of recovery from surgical lesions to the brain?

-Dorsolateral frontal lesions (no recovery in card sorting)
-Right temporal lesions (no recovery on the Rey Figure)
-Bilateral temporal lobe removal (no recovery)
-Left temporal lesions (significant improvement after 5-20 years)

15

What are some examples of functional restitution in every day life?

-When employment is used as a measure of recovery, an 80% recovery rate is found
-Social relationships and leisure activities suffer (relationships with siblings suffer the most)
-Measures of recovery often overlook the coping mechanisms the person is using

16

What are the post-stroke changes found in individuals using functional imagine?

-Functional improvement can be found in the sensorimotor cortex
-Movement of the limbs activates cortex along the rim of the injury and often activates regions of the face area
-Larger regions of activation in the parietal and premotor areas during language and motor functions
-Reorganization takes place bilaterally
-Capacity for reorganization declines with increases in stroke size and age
-Considerable variability exists between patients

17

What was found when the digit area of a monkey's cortex was removed?

-Without rehabilitation, the shoulder and elbow area grew into that part of the motor cortex
-With rehabilitation, the finger area grew back in the cortex

18

What are the variables that affect recovery?

-Age (younger patients = more recovery)
-Sex and Handedness (produce differences in cerebral organization that influence outcome)
-Intelligence (higher intelligence = more recovery)
-Personality (optimism, extroversion, and easygoing patients = more recovery)

19

What are the six therapeutic approaches to brain damage?

-Rehabilitation
-Movement therapy
-Cognitive rehabilitation
-Pharmacological therapies
-Brain stimulation
-Brain tissue transplants and stem-cell induction

20

What is the information on the therapeutic approach of rehabilitation?

-Little information on programs
-Social interaction and environmental stimulation are important

21

What is the information on movement therapy?

-Constrained movement therapy
-Motor training stimulates plastic changes in the brain

22

What is the information on cognitive rehabilitation?

-Hard to develop real world tasks that will benefit the patient outside of the clinic
-Substitution systems

23

What is the information on pharmacological treatments?

-Compounds can facilitate plastic changes in the brain
-Can be used shortly after brain injury
-Work by reducing inflammation

24

What is the information on brain stimulation?

-TMS
-Promising without complications

25

What is the information for brain tissue transplants or stem cell induction?

-Fetal stem-cell transplants for Parkinson’s patients
-Could cultivate stem cells from the individual’s body
-Not very promising/successful so far