plasticity and functional recovery

what is brain plasticity

the brains ability to change and adapt as a result of experience. Recent research suggests that the brain creates new neural pathways and alters existing ones as a result of learning throughout our entire life

what are 3 factors affecting plasticity

life experiences

video games

meditation

how do life experiences impact plasticity

frequently used nerve pathways develop stronger connections while rarely/never used neurons die

There is also a natural decline in cognitive functioning with age causing changes in the brain

how does playing video games impact plasticity

playing video games makes complex motor and cognitive demands on the brain, improving areas like spatial navigation, strategic planning, memory, and motor performance

who studied the effects of gaming on brain plasticity

Kuhn et al

trained participants for 30 mins a day for 2 months on super mario

found gray matter increased in the cortex, hippocampus, and cerebellum

created new synaptic connections in areas involved in spatial navigation , strategic planning, memory, and motor performance

how does meditation impact brain plasticity

found to change the inner workings of the brain both short and long term

Study to show the impact of meditation on brain plasticity

Davidson et al

compared 8 tibetan monks to 10 students who did not meditate

found that the monks showed a greater increase in gamma activity when meditating than the students

what is functional recovery

the brains ability to transfer functions from damaged to undamaged areas following trauma

this enables the recovery of abilities and mental processes that have been compromised die to brain injury or disease

what shows functional recovery

Stroke patients’ brains are able to be rewired over time even after brain cells had been damaged or destroyed

what are the types of functional recovery

axon sprouting

denervation supersensitivity

neural unmasking

stem cells

what is axon sprouting

when an axon is damaged the connections with neighbouring neurons are lost

axons that already connect with that neuron may sprout extra connections replacing the ones that have been lost, compensating for the loss of a neighbour

this occurs in the 2 weeks after damage and can help replace function

the damaged axon and compensatory axon must do a similar job otherwise problems can occur with function

what is denervation supersensitivity

occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost

however this can lead to over sensitivity of messages such as pain

what is neuronal unmasking

Wall (1977) dormant synapses in the brain exist but are blocked due to low rates of neural input

increasing the rate of input can open or ‘unmask’ these dormant synapses and open connections to unused areas of the brain to aid development of new structures

how are stem cells used in functional recovery

stem cells have potential to take on a variety of functions so when implanted in the brain they can replace damaged cells

they may also rescue injured cells as they secrete growth factors

they can also create a neural network linking an uninjured brain site to the damaged areas

AO3 for plasticity AND functional recovery

plasticity has research support from animal studies

plasticity has research support from animal studies

functional recovery has research support from animal studies

there may be age differences with functional recovery and plasticity

educational attainment may impact functional recovery

plasticity and functional recovery have practical applications

plasticity has research support from animal studies

Kempermann et al suggested an enriched environment could alter the number of neurons in the brain

They found evidence of an increased number of new neurons in the brain of rats housed in a complex environment compared to those in lab cages. This was seen particularly in the hippocampus (formation of new memories and navigation of new places)

This shows clear evidence of the brains ability to change as a result of experience, demonstrating plasticity

BUT there is a question of generalisability from rats to humans

plasticity has research support from human studies

Maguire et al studied london taxi drivers and found that changes in the brain could be detected as a result of their extensive use of spatial recognition. Using MRI, researchers calculated the amount of gray matter in the brains of taxi drivers and a control group and found that taxi drivers had a larger hippocampus. Volume of the posterior hippocampus was directly correlated to the time spent as a taxi driver

This shows not only that job related experiences can affect the brain such as the hippocampus, but that the highest levels of plasticity were evident in those with more extensive experience, providing evidence for plasticity

Functional recovery has research support from animal studies

Tajiri et al randomly assigned rats with traumatic brain injury into 2 groups. One group received transplants of stem cells into the affected brain region, while the control group received a solution without stem cells. After 3 months, the stem cell group showed clear development of neuron like cells in the area of injury, and a solid stream of stem cells migrating to the injury site. This development was not evident in the control group so it supports the important role played by stem cells in recovery from brain injury

There are age differences in functional recovery and plasticity

functional plasticity reduces with age. It was suggested that the only option following traumatic brain injury beyond childhood is to develop compensatory strategies to work around the deficit. However recent studies have suggested that even abilities thought to be fixed in childhood can be modified in adulthood with intensive retraining

despite this suggesting adult plasticity and functional recovery, the capacity for neural reorganisation seems to be greater in children than adults, aa adults require extensive practice to see change

Educational attainment impacts functional recovery

Schneider et al found that participants with a college level education are 7x more likely to be disability free 1 yr after a moderate to severe traumatic brain injury compared to those who didn't finish high school. They carried out a retrospective study using data from the US Traumatic Brain Injury Systems data base. Of the 796 patients studies 214 achieved disability free recovery after 1 yr. 39.2% who had 16+ yrs education reached DFR compared to 30.8% with 12-15 yrs and only 9.7% of those with under 12 yrs education.

The researches concluded that cognitive reserve which is associated with educational attainment was an important factor in functional recovery- meaning there are individual differences

Plasticity and functional recovery have practical applications

Both plasticity and functional recovery can be applied to neurorehabilitation. This uses motor therapy and electrical stimulation to the brain to counter the effects of brain injury on cognitive and motor functions

This demonstrates the practical applications of the understanding of functional recovery and brain plasticity in improving the recovery and cognitive functioning of those recovering from traumatic brain injury