brain plasticity and functional recovery

• • Brain plasticity refers to the brains ability to change and adapt its structure and function in response to experiences, learning and injury 
• Research into brain plasticity:

  Maguire et al-

  • Taxi drivers have a larger posterior hippocampi and more volume of grey matter within this area, compared to non-taxi drivers. This shows how experiences (navigational knowledge in this case) can lead to brain plasticity - also found a positive correlation between length of time on the job and the more pronounced structural difference 

  Draganski et al - 

  • Imaged brains of medical students 3 months before and after their final exams and found evidence of learning-induced changes in the posterior hippocampus and parietal cortex  
• Functional recovery:

  • When the brain regains abilities that were once lost due to damage - such as from a stroke 
  • This occurs because the brain can recognise itself - forming new neural pathways to take over functions that were previously controlled by these damaged areas - known as neuronal unmasking
• Neuronal unmasking:

  • A process where previously unused or inactive synapses in the brain become active when they are needed - such as when there is damage to the brain 
• neuronal unmasking:

  • When brain damage occurs, the usual pathways may be disrupted or destroyed. As a result, the brain looks for alternative ways to process information and function
  • When a part of the brain is damaged, the reduced neural input (fewer signals being sent) triggers the nearby dormant synapses to become active 
• Structural changes that support the process of neuronal unmasking:

  • Axon sprouting - new nerve endings grow from surviving neurones to create alternative pathways 
  • Reformation of blood vessels- new blood vessels form to supply oxygen and nutrients to damaged areas - aiding recovery 
  • Denervation super-sensitivity - when neurones that do siminalr jobs become more sensitive to compensate for lost function - possible negative consequences of oversensitivity 
  • Recruitment of homologous of areas - the same areas of the brain on the opposite hemisphere takes over the lost function