plasticity and functional recovery

• As people gain new life experiences, nerve pathways that are used frequently develop stringer connections, neurons that are rarely used, will eventually die. By developing new connections, the brain is able to constantly adapt to changing environments. However, there is also a natural decline in cognitive functioning with age due to changes in the brain. Boyke found, when 60 yr olds were taught a new skill (juggling), there was an increase in grey matter in the brain, which was reversed when practising was stopped.
• . Playing video games were also found to make cognitive and motor demands. A study was done, a control group was compared with a training group who spent a least 30 mins a day, for 2 months on Super Mario. An increase in grey matter in areas including the hippocampus and cerebellum was found. Researchers concluded that video game training resulted in new synaptic connections.
• A study was also done with 8 monks a 10 student volunteers. Both groups were fitted with electrical sensors and asked to meditate for short periods. There was an increase in gamma activity while meditating. These changes were short term; however it can produce permanent changes due to the monks having far more gamma activity than the control group before it even started.
• In the 1960s researchers studied cases where people regained functioning after strokes. Neurons next to the damage brain areas can form new circuits. Regenerative developments in brain function arise from the brain’s plasticity. Wall first identified ‘dormant synapses. These exist anatomically but function is blocked. If there is an increasing rate of input to these systems (if areas around became damaged), they can unmask these synapses. This can open connections to the brain that aren’t normally activated and develop new structures.

   
• Stem cells are unspecialised calls that have potential to carry out different functions, including characteristics of nerve cells. There are different views on how they work, one is that they replace dead or dying cells. The second is they somehow ‘rescue’ these cells.

   
• FRT It is a commonly accepted view that functional plasticity reduces with age.

  according to this view, the only option following traumatic brain injury beyond childhood is to develop compensatory behavioural strategies to work around the deficit (e.g. seeking social support) However, studies have suggested that even abilities commonly thought to be fixed in childhood can still be modified in adults with intense retraining. 

  it was concluded that the capacity for neural reorganisation is much greater in children than in adults.
• FRT Tajiri 2013 provided evidence support from role of stem cells in brain injury recovery.

  They randomly assigned rats with traumatic brain injury to one of two groups. One group received transplants of stem cells into the region of the brain affected by traumatic injury. The control group received a solution infused into the brain containing no stem cells. 3 months later, the brains of stem cell rates have shown clear development of cells in area of injury.

  This development of cells wasn’t evident in the control group, supporting the important role of stem cells.
• Maguire in a study of London taxi drivers, found changes in brains could be due to experience of spatial navigation.

  Using MRI scanner, researchers calculated amount of grey matter in the brains of taxi drivers and control pt. The posterior hippocampi of taxi drivers were larger compared to control pt and posterior hippocampal volume was positively correlated with amount of time as a taxi driver. This shows that hippocampal volume was greater in those individuals with job related experience of spatial navigation, and that highest levels of plasticity were evident in those with more experience.
• A researcher suggested that an enriched environment could alter the number of neurons in the brain. They found evidence of an increased number of new neurons in the brains of rats housed in complex environments compared to rats in laboratory cages. In particular, the rats housed in the complex environment showed an increase in neurons in the hippocampus, which is associated with the formation of new memories and ability to navigate. This shows clear evidence of the brain's ability to change as a result of experience, i.e. it demonstrates plasticity.