Plasticity and functional recovery of the brain after trauma

• Plasticity and functional recovery of the brain after trauma

  Brain plasticity

  The brains tendency to change and adapt (functionally and physically) as a result of experience and new learning. During infancy, the brain experiences a rapid growth in the number of synaptic connections it has, peaking approx 15,000 synapses per neuron at age 2-3 years. As we age, rarely used connections are deleted and frequently used connections are strengthened - synaptic pruning.
• Plasticity and functional recovery of the brain after trauma

  Research into plasticity

  Maguire et al. (2000) studied brains of London taxi drivers and found sig more volume of grey matter in the posterior hippocampus (associated w/ spatial and navigational skills) than in matched control group. The longer they had been in the job, the more pronounced was the structural difference (positive correlation).
• Plasticity and functional recovery of the brain after trauma 3

  Functional recovery of the brain after trauma

  Following physical injury, or other forms of trauma such as a stroke, unaffected areas of the brain are often able to adapt and compensate for those areas that are damaged. Neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks or moths. At this point the individual may require rehabilitative therapy to further their recovery.
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  What happens in the brain during recovery?

  Is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage. Process supported by number of structural changes in the brain:

  • axonal sprouting - growth of new nerve endings which connect w/ other undamaged nerve cells to form new neuronal pathways.
  • Reformation of blood vessels
  • recruitment of homologous areas on the opposite side of the brain to perform specific tasks.
• Plasticity and functional recovery of the brain after trauma- evaluation

  Practical application. Understanding processes involved in plasticity has contributed to field of neurorehabilitation. Spontaneous recovery tends to slow down after a number of weeks so forms of physical therapy may be required to maintain improvements in functioning. E.g., movement therapy to counter deficits in motor functioning that may be experienced following a stroke. Shows that although brain has capacity to 'fix itself' to a point, process requires further intervention to be completely successful.
• Plasticity and functional recovery of the brain after trauma- evaluation 2

  Brain's ability to rewire itself can sometimes have maladaptive behavioural consequences. Prolonged drug use has been shown to result in poorer cognitive functioning as well as increased risk of dementia in later life. Also, 60-80% of amputees have been known to develop phantom limb syndrome (continued experience of of sensations in the missing limb as if it were still there). Sensations usually unpleasant, painful and thought to be due to cortical reorganisation in the somatosensory cortex.
• Plasticity and functional recovery of the brain after trauma- evaluation 3

  Functional plasticity tends to reduce w/ age. Brain has greater propensity for reorganisation in childhood as is constantly adapting to new experiences and learning. That said, Bezzola et al. (2012) demonstrated how 40 hrs of golf training produced changes in neural representation of movement in ppts aged 40-60. Using fMRI, researchers observed reduced motor cortex activity in golfers compared to control group, suggesting more efficient neural reps after training. Shows neural plasticity continues throughout lifespan.