Functional Recovery after Trauma

Question 1

Define functional recovery

Answer 1

Following physical injury or other forms of trauma such as infection
or a stroke, unaffected areas are sometimes able to adapt or compensate for those areas that are damaged.

This functional recovery is an example of neural plasticity. Neuro
scientists suggest that this can happen quickly after trauma
(spontaneous recovery) and then slow down after several weeks or
months. Therapy may then be needed.

Question 2

Mechanisms for recovery: Axon sprouting

Answer 2

Growth of new nerve endings which connect with undamaged cells to form new neural pathways, to compensate for damaged
nerves.

These new branches are called collateral sprouts

Question 3

Mechanisms for recovery: Denervation Supersensitivity

Answer 3

This occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost

However, it can have the negative consequence of oversensitivity to messages such as pain.

Question 4

Mechanisms for recovery: Neuronal unmasking

Answer 4

‘Dormant synapses’ exist anatomically but their function is blocked. Normally these are ineffective because the rate of neural activity is too low for them to be activated

However, if there is damage to a surrounding brain area this can
increase the rate of input sufficiently to open (or ‘unmask’) these dormant synapses.

This can open connections to areas of the brain not normally activated; which can in time lead to a development of new structures.

Question 5

Mechanisms for recovery: Stem Cells

Answer 5

Stem cells are unspecialised cells that can take on the characteristics of different cells including nerve cells.

Stem cells may provide treatment for brain damage; there are three possible views on how transplanted stem cells work:

• directly replace dead/dying cells
• secrete growth factors that ‘rescue’ the damaged cells
• create a network linking an uninjured brain site, where new stem cells are made, to the damaged region