Plasticity & Functional Recovery Of The Brain After Trauma

Question 1

Define ‘plasticity’.

Answer 1

The ability of the brain to change & adapt functionally & physically in response to experience.

Question 2

What happens during infancy?

Answer 2

The brain experiences rapid growth in the number of neurons & synaptic connections; by the age of 2-3, an infant has more neurons & connections than in a mature adult brain. This decline can be explained the process of synaptic pruning.

Question 3

What was originally thought about brain plasticity in adulthood?

Answer 3

That brain plasticity was not present in adulthood after the brain reaches the critical period of maturity at the age of 20. However, recent research suggests that although plasticity is less evident in the later life, new neural connections can be formed as a result of learning & experience. This can be explained by different functional demands at different ages. In infancy, the range of new experiences means the brain has to adapt drastically, whereas, in adulthood there may be more specific demands requiring only certain areas of the brain to adapt.

Question 4

Define ‘functional recovery’.

Answer 4

A form of plasticity whereby, following damage to the brain through trauma, the brain is able to redistribute the functions of the damaged areas to undamaged parts that would not usually perform them.

Question 5

What are the different ways the undamaged areas of the brain may compensate in response to the damage?

Answer 5

• Neural reorganisation: a different area of the brain adopts the functions of the damaged area.
• Axonal sprouting: the growth of new nerve endings from surviving neurons which then connect to areas of the brain the damaged neurons used to connect to.
• Neural regeneration: the growth of completely new neurons.
• Reformation of blood vessels may result if cerebral haemorrhage or cerebral ischaemia has damaged the blood supply to the affected areas.