Plasticity after Brain Damage

closed head injury

• the most common cause of brain damage is — ,

• — a sharp blow to the head that does not puncture the brain

cerebrovascular accident.

A common cause of brain damage is temporary interruption of normal blood flow to a brain area during a stroke, also known as a —

ischemia

• The more common type of stroke is —

• the result of a blood clot or other obstruction in an artery

hemorrhage

• The less common type of stroke is —

• the result of a ruptured artery

tissue plasminogen activator (tPA)

• A drug called —breaks up blood clots.

• To get a benefit, a patient should receive — quickly, at least within 4.5 hours after a stroke.

cannabinoids

Exposure to — (the chemicals found in marijuana) minimizes the damage caused by strokes in laboratory animals.

Diaschisis

— from a Greek term meaning “to shock throughout”) refers to the decreased activity of surviving neurons after damage to other neurons

fish

Damaged axons also grow back in the spinal cord of a —, under the control of a gene that is ac tive in glia cells

mammalian

axons do not grow back in the — brain or spinal cord, at least not enough to pro duce any benefit.

collateral sprouts

After a cell loses input from an axon, it secretes neurotrophins that induce other axons to form new branches, or —-, that take over the vacant synapses

denervation supersensitivity

• Conversely, if a certain set of synapses becomes inactive, perhaps because of damage elsewhere in the brain- the remaining synapses become more responsive, more easily stimulated.

• This process of enhanced response, known as —-or receptor supersensitivity, has been demonstrated mostly with dopamine synapses

phantom limb

• Physicians have long noted that many people with amputations experience a —-,

• a continuing sensation of an amputated body part