Neural Plasticity

Question 1

Areas of potential adult neurogenesis

Answer 1

Dentate gyrus
Subventricular zone

Question 2

Dentate gyrus neurogenesis

Answer 2

Type 1 cells: astrocytes (radial astrocytes)
Median turnover rate of 1.75% in hippocampus

Question 3

Subventricular zone neurogenesis

Answer 3

Ventricle lined with ependymal cells
A cell: neuron
B cell: astrocytes (can make more astrocytes or proliferative precursor)
C cell: proliferative precursor
Also viewed in striatum

Question 4

Mechanism of migration to olfactory bulb

Answer 4

Rostral migratory stream

Question 5

Rostral migratory stream

Answer 5

Astrocytes bundle new neutrons and migrate them to olfactory bulb where they are integrated into olfactory system

Question 6

Neuroplasticity & exercise

Answer 6

Exercise increases amount of BDNF in dentate gyrus of hippocampus
Greater exercise = more BDNF
Improves executive (most), controlled, spatial, and speed tasks

Question 7

Brain derived neurotrophic factor (BDNF)

Answer 7

Both anterograde and retrograde transport
Increases synaptic activity
Influences gene transcription
Precipitates changes in synaptic structures
Increases neural health

Question 8

Neuroplasticity & Diet

Answer 8

Restrict energy intake to increase neuronal growth in hippocampus
Restrict caloric intake by 30% over three months increased memory
Increases neurotrophic, antioxidants, removal of damages molecules
Reduces inflammation, oxidative stress
Intermittent energy restriction involves hormesis (exposure of cells and organisms to mild stress to protect against severe stress)

Question 9

Neuroplasticity & Learning

Answer 9

Training and practice increase neural plasticity
E.g. training monkeys on finger dexterity increases primary motor cortex area
Violinists and juggling have similar changes

Question 10

Closed head injury

Answer 10

Sharp blow to the head that does not puncture brain

Question 11

Cause of damage in closed head injury

Answer 11

Rotational forces that drive brain tissue against the inside of the skull
Blood clots that interrupt blood flow to the brain

Question 12

Impact deceleration injuries

Answer 12

Normal brain position before contact with an obstacle
Coup injury where the brain is compressed against the skull at the point of contact with the obstacle
Contrecoup injury where the brain i compressed against the skull at the point opposite to the point of contact after rebound

Question 13

Hematoma

Answer 13

In meninges or cerebrum
Bad bruise

Question 14

Contusion

Answer 14

Localized bruising, small tears in blood vesselsD

Question 15

Diffuse axonal injury

Answer 15

Axonal sheering as the brain moves within the skull case
Diffuse brain swelling occurs after traumatic brain injury

Question 16

Excitoxicity

Answer 16

Over activity of the nutrient starved cells

Question 17

Stroke/cerebrovascular incident

Answer 17

Temporary interruption of normal blood flow to brain area

Question 18

Ischemia

Answer 18

Result of a blood clot or other obstruction in an artery
Most common
Neurons deprived of blood lose much of their oxygen and glucose supplies

Question 19

Hemorrhage (intracerebral hemorrhage)

Answer 19

Result of a ruptured artery
Less common
Neurons flooded with blood and excess oxygen, calcium, and other chemicals

Question 20

Edema

Answer 20

Accumulation of fluid
Both types of strokes lead to this
Increases pressure on brain
Increases chance of future strokes

Question 21

Penumbra

Answer 21

Halo of damage around area of stroke
Denervation and spine collapse
Surviving neurons in penumbra show reduced activity
Inhibition of axon growth

Question 22

Denervation

Answer 22

Death of some neurons deprives some dendrites of synaptic input

Question 23

Spine Collapse

Answer 23

Spines on dendrites shrink or disappear

Question 24

Effects of stroke

Answer 24

Edema
Penumbra
Impair sodium potassium pump
Excess release of transmitter glutamate

Question 25

Tissue plasminogen activator (tPA)

Answer 25

Drug that breaks up blood clots
Makes hemorrhage worse because hemorrhage results from rupture blood vessel and not blood clot
Physicians usually administer tPA because hemorrhage is less common and typically fatal anyway
Needs to be received quickly (within 4.5 hours of stroke)
Drawbacks: most people don’t get to the hospital quickly enough (don’t realize they’ve had a stroke)

Question 26

Other treatment options for stroke

Answer 26

Cooling the brain
Antioxidants
Antibiotics
Albumin
Treatments affecting Immune system
Exposure to cannabinoids

Question 27

Cell genesis

Answer 27

brain attempts to recover the function after a brain injury by increasing the production of new cells

Question 28

Diaschisis

Answer 28

Decreased activity of surviving neurons after damage to other neurons

Question 29

Connectional diaschisis

Answer 29

Reduced connectivity among areas distant from a stroke (beyond penumbra)

Question 30

Functional Diaschisis

Answer 30

Localized distal reduction in activity in response to stimulation or due to behaviour

Question 31

Phantom Limb

Answer 31

Continuing sensation of an amputated body part
Functional reorganization in cortex can occur after somatosensory and motor areas are deprived of regular input (loss of limb)
Can range from tingling to intense pain (occasionally or constantly)
Could last days, months, years, lifetime