Brain Plasticity and Functional Recovery

• Plasticity definition


  • The tendency to change and adapt (functionally and physically) as a result of experience and new learning
  • Brain continues to create new neural pathways and later existing ones in response to changing experience
• (A)PFC - Video Game study (Kuhn et al)


  P - Compared a control group with a video game training group that was trained for 2 months for at least 30 minutes on the same video game

  F - Found a significant increase in grey matter in various brain areas including the cortex, hippocampus and cerebellum, which was not evident in the control group

  C - Concluded that the video game training had resulted in new synaptic connections in brain areas involved in spacial navigation, strategic planning and working memory and motor performance - skills that were important in playing the game successfully
• Plasticity AO3 - Research support


  • Maguire et al studied the brains of London taxi drivers using an MRI scan
  • Found significantly more grey matter in the posterior hippocampus
  • Brain scans showed a particularly large posterior hippocampus, a region associated with two dimensional spatial processing
  • Largest in taxi drivers with more than 40 years of experience
  • Suggesting the longer they had been doing the job the more pronounced was the structure of difference as the brain changed and adapted to accommodate new learning
• Plasticity AO3 - Animal study support


  • Kemperman et al found evidence of an increased number of neurons in the brains of rats housed in complex environments compared to rats housed in cages
  • The rats housed in complex environments showed an increase in neurons in the hippocampus (associated with formation of new memories)
  • Suggesting that the experience of a new environment led to plasticity and gave the rats the ability to navigate from one location to another
• Plasticity AO3 - Real life application


  • Examining plasticity and functional recovery provides application to the field of neurorehabilitation
  • Understanding the processes of plasticity and functional recovery led to the development of neurorehabilitation which uses motor therapy and electrical stimulation to counter the negative effects and deficits in motor and cognitive functions following injuries
  • This demonstrates the positive application of research in this area to help improve the cognitive functions of people suffering from injuries
• What is the definition of functional recovery?

  The brain’s ability to adapt or compensate for damaged areas following physical injury/trauma
• What are the structural changes that occur during neuronal unmasking?

  • Secondary neural pathways are unmasked
  • Axon sprouting: new nerve endings grow and connect with undamaged areas
  • Reformation of blood vessels
  • Recruitment of homologous areas on the opposite hemisphere for specific tasks
• What is axon sprouting?

  New nerve endings grow and connect with undamaged areas
• How do stem cells contribute to brain recovery?

  They implant into the brain replacing dead or dying cells and secrete growth factors
• What role do transplanted stem cells play in brain recovery?

  They form a neural network linking uninjured brain sites with damaged regions
• What happens during neuronal unmasking?

  Dormant synapses become unmasked and activated by increased neural input
• What are the effects of neuronal unmasking on brain function?

  • Opens connections to usually inactive brain regions
  • Creates a spread of activation
  • Facilitates the development of new structures
• Functional recovery AO3 - Research support


  • Taijiri et al provided evidence for the role of stem cells in recovery from brain injury using rats
  • One group received transplants of stem cells into region of the brain affected by traumatic injury
  • Control group received a solution infused into the brain containing no stem cells
  • Three months after the brain injury the brains of stem cell rats showed a clear development of neuron like cells in the area of injury
  • Accompanied by a solid stream of stem cells migrating to the brain’s site of injury which was not the seen with the control group
• Functional recovery AO3 - Age differences

  • Commonly accepted view that functional plasticity reduces with age (Huttenlocher) - only option following traumatic brain injury beyond childhood must be to develop compensatory behavioural strategies to work around the deficit
  • However studies have suggested that even abilities thought to be fixed in childhood can still be modified with intense retraining
  • Elbert et al conclude that the capacity for neural reorganisation is much greater in children than in adults, as demonstrated by the extended practice that adults require to produce changes
• Functional recovery AO3 - Educational attainment


  • Schneider et al discovered that the more time brain injury patients had spent in education - their 'cognitive reserve' - the greater their chances of a disability free recovery
  • Two-fifths of patients studied who achieved disability free recovery had more than 16 years education compared to about 10% of patients who had less than 10 years of education
  • Concluded that 'cognitive reserve' (associated with greater educational attainment) could be a factor in neural adaptation during recovery from traumatic brain injury