Bio - Plasticity & functional recovery of the brain Flashcards
What is brain plasticity?
Refers to the brain’s ability to modify its own structure and function as a result of experience.
What is functional recovery?
Refers to the recovery of abilities and mental processes that have been compromised as a result of brain injury or disease.
What are some factors that are known to affect neuronal structure and function?
Life experience, video games and meditation.
Life experiences could include; learning new skills, a result of developmental changes, response to direct trauma to an area/areas of the brain, response to indirect effects of damage such as brain swelling or bleeding (from stroke).
How does life experience affect plasticity?
As people gain new experiences, nerve pathways that are frequently used develop stronger connections, whereas neurons that are rarely used eventually die. By developing new connections and pruning away weak ones, the brain is able to constantly adapt to the changing environment.
By developing new connections and pruning away weak ones, what is the brain able to do?
Constantly adapt to the changing environment.
What changes to do with age can be attributed to the brain?
There is a natural decline in cognitive functioning.
What research has been done into plasticity in older ages?
Researchers are looking for ways in which new connections can be made to reverse the effect of age.
For example, Boyke et al. (2008) found evidence of brain plasticity in 60 year olds taught a new skill - juggling. They found increases in grey matter in the visual cortex, although when practising stopped, these changes were reversed.
How does playing video games affect plasticity?
Playing video games makes many different complex cognitive and motor demands and so as a result the researchers concluded that video game training had resulted in new synaptic connections in brain area involved in spatial navigation, strategic planning, working memory and motor performance - skills that were important in playing the game successfully.
What evidence is there for the fact that playing video games has an effect on plasticity?
Kuhn et al. (2014) compared a control group with a video game training group that was trained for two months for at least 30 mins per day on the game Super Mario.
They found a significant increase in grey matter in various brain areas including the cortex, hippocampus and cerebellum. This increase was not evident in the control group that did not play Super Mario.
The researchers concluded that video game training had resulted in new synaptic connections in brain area involved in spatial navigation, strategic planning, working memory and motor performance - skills that were important in playing the game successfully.
How does meditation affect plasticity?
Meditation not only changes the workings of the brain in the short term, but may also produce permanent changes, based on the fact that far more gamma wave activity was found in those who meditated than those who didn’t.
What evidence is there for the fact that meditation has an effect on plasticity?
Researchers working with Tibetan monks have been able to demonstrate that meditation can change the inner workings of the brain. Davidson et al. (2004) compared eight practitioners of Tibetan meditation with 10 student volunteers with no previous meditation experience.
Both groups were fitted with electrical sensors and asked to meditate for short periods. The electrodes picked up much greater activation of gamma wave activity while meditating.
The researchers concluded that meditation not only changes the workings of the brain in the short term, but may also produce permanent changes, based on the fact that the monks had far more gamma wave activity than the control group even before they started meditating.
What are the mechanisms for recovery?
Neuronal unmasking and stem cells.
Who discovered neuronal unmasking and how?
Wall (1977) first identified what he called ‘dormant synapses’ in the brain. These are synaptic connections that exist anatomically but their function is blocked.
Describe neuronal unmasking as a mechanism for recovery
Wall (1977) first identified what he called ‘dormant synapses’ in the brain. These are synaptic connections that exist anatomically but their function is blocked.
Under normal conditions these synapses may be ineffective because the rate of neural input to them is too low for them to be activated. However, increasing the rate of input to these synapses, as would happen when a surrounding brain area becomes damaged, can then open (or ‘unmask’) these dormant synapses.
The unmasking of dormant synapses can open connections to regions of the brain that are not normally activated, creating a lateral spread of activation which, in time, gives way to the development of new structures.
What are stem cells?
Specialised cells that have the potential to give rise to different cell types that carry out different functions, including taking on characteristics of nerve cells.
How are stem cells a mechanism for recovery?
They have the potential to give rise to different cell types that carry out different functions, including taking on characteristics of nerve cells.
They might work to provide treatments for brain damage caused by injury of neurodegenerative disorders by:
- Being implanted into the brain to directly replace dead or dying cells.
- Being transplanted to secrete growth factors that somehow ‘rescue’ the injured cells.
- Being transplanted so they form a neural network, which links an uninjured brain site, where new stem cells are made, with the damaged region of the brain.
