Plasticity & Functional Recovery of Brain after Trauma

• Brain plasticity

  Brain's ability to reorganise neural pathways due to experience (learning causes brain changes)
• Critical period for brain development

  • Childhood - 15,000 synaptic connections at 2-3 y/o (Gopnik et al. 1999)
  • Neuroplasticity occurs throughout lifespan
• Types of neuroplasticity

  • Dendrite branching (synapse strengthened by task repetition)
  • Neural (synaptic) pruning (eliminating unused neural (synapses) networks)
• Maguire et al. 2000 study


  • MRI brain scans of 16 male London taxi drivers have more volume of grey matter in posterior hippocampus (area of spatial and navigational skills)
  • Result of test of city street and route recollection 'The Knowledge' altered their brain structure
  • Longer experience as taxi driver = more pronounced structural difference - quasi, matched pairs, compared to 16 males non taxi drivers
• Danelli et al. 2013 study


  • Case study of 14 y/o EB; brain tumour in LH - at 2y/o had hemispherectomy of LH therefore language Broca and Wernicke centres are gone
  • Lost all language ability but recovered it after 2 years, developed dyslexia-like symptoms, FMRI scans shows RH function like the LH
  • Conclusions = RH replicated LH therefore brain can adapt and recover post damage
• Draganski et al. 2006 study


  • Changes in posterior hippocampus and parietal cortex in brains of medical students pre and post exam
• Mechelli et al. 2004 study

  • Larger parietal cortex in bilinguals' brains
• Functional recovery of brain after trauma

  Example of neural plasticity where unaffected areas compensate and adapt for damaged/destroyed area
• Spontaneous recovery

  • Occurs quickly post-trauma then slows down therefore needs rehabilitative therapy
• Denervation supersensitivity

  Axons of a similar job become better
• Brain during recovery

  • Secondary neural pathways to carry functions of affected areas to enable continued function (Doidge 2007)
  • Axonal sprouting (new nerve endings grow to connect to nerve cells and form new pathway)
  • Reformation of blood vessels
  • Recruitment of homologous areas on opposite side of brain (functionality moves to opposite side of affected area then may shift back after time)