5.2 Plasticity After Brain Damage

Question 0

The possible cause of brain damage include ____, ____, exposure to ____ or ____ substances, and degenerative conditions such Parkinson’s disease and Alzheimer’s disease.

Answer 0

tumours, infections, exposure to radiation or toxic

Question 1

Almost all survivors of brain damage show ____ recovery to some degree.

Answer 1

behavioural

Question 2

In young people, the most common cause in ____ ____ ____, a sharp blow to the head resulting from an accident or assault that does not puncture the brain.

Answer 2

closed head injury

Question 3

____ head injuries, common in certain sports, are more worrisome. After a severe head injury, recovery is slow and often incomplete.

Answer 3

Repeated

Question 4

One cause of damage after closed head injury is the ____ ____ that drive brain tissue against the inside the skull. Another cause is blood clots that interrupted bloodflow to the brain.

Answer 4

rotational forces

Question 5

A common cause of brain damage, especially older people, is temporary interruption of normal blood flow to a brain area during a ____, also known as a ____ accident.

Answer 5

stroke : cerebrovascular

Question 6

The more common type of stroke is ____, the result of a blood clot or other obstruction in an artery.

Answer 6

ischemia

Question 7

The least common type of stroke is ____, the result of a ruptured artery.

Answer 7

hemorrhage

Question 8

And ischemia, the neurons deprived of blood lose much of their ____ and ____ supplies.

Answer 8

oxygen and glucose

Question 9

In haemorrhage, the neurons are flooded with blood and excess ____, ____ and other chemicals.

Answer 9

oxygen, calcium

Question 10

Both ischemia and haemorrhage lead to many of the same problems, including ____ (the accumulation of fluid), which increases pressure on the brain and the probability of additional strokes.

Answer 10

edema

Question 11

Both ischemia and haemorrhage also impair the ____ pump, leading to an accumulation of sodium inside neurons.

Answer 11

sodium-potassium

Question 12

Today, prospects are good for ischemia if physicians act quickly. A new drug called ____ ____ ____ (tPA) breaks up blood clots. To get significant benefit, a patient should receive tPA within three hours after stroke, although slight benefits are possible during the next several hours.

Answer 12

tissue plasminogen activator

Question 13

TPA can make matters worse in a haemorrhage. The usual decision is to give the tPA. Haemorrhage is less common and usually ___ anyway, so the risk of making a haemorrhage worst is small compared to the hope of alleviating ischemia.

Answer 13

fatal

Question 14

The most effective known method of preventing brain damage after strokes in laboratory animals is to ____ the brain.

Answer 14

cool

Question 15

Another procedure might surprise you: exposure to ____ (chemicals found in marijuana) minimise the damage caused by strokes in laboratory animals.

Answer 15

cannabinoids

Question 16

Research on laboratory animals indicates that cannabinoids are most effective if taken shortly ____ the stroke. It would be difficult to apply that advice in humans.

Answer 16

before

Question 17

After the first days following brain damage, many of the surviving brain areas ____ or ____ their activity. In some cases, one area more or less takes over the function of another, damaged area.

Answer 17

increase or reorganise

Question 18

In other cases, surviving brain areas do not take over the functions of the damaged area, but they ____ in various ways.

Answer 18

compensate

Question 19

A behavioural deficit after brain damage reflects more than just the cells that died. After damage to any brain area, other areas that have lost part of their normal input become less ____.

Answer 19

active

Question 20

____ refers to the decreased activity of surviving neurons after damage to other neurons.

Answer 20

Diaschisis

Question 21

If diaschisis contributes to behavioural deficits following brain damage, then increased ____ should help.

Answer 21

stimulation

Question 22

____ drugs also promote recovery in brain damage.

Answer 22

Stimulant

Question 23

With impaired movement or depth perception in laboratory animals, injecting ____ significantly enhanced both behaviours, and animals that practised behaviours under the influence of amphetamines showed long-lasting benefits.

Answer 23

amphetamines

Question 24

With impaired movement or depth perception in laboratory animals, injecting a different drug to block dopamine synapses ____ behavioural recovery.

Answer 24

impaired

Question 25

Although amphetamine is too risky for use with human patients, other stimulant drugs are more promising. A related idea is to use drugs that block the release of ____, the brains main inhibitory neurotransmitter.

Answer 25

GABA

Question 26

Although a destroyed cell body cannot be replaced, damaged axons do ____ ____ under certain circumstances.

Answer 26

grow back