Plasticity and functional recovery from brain trauma Flashcards
good day
ok move on im done
Denervation
Loss of nerve supply inactivity and atrophy of muscle fibres
Plasticity
The brain’s tendency to change and adoptas a result of experience and new learning
Denervation supersensitivity/hypersensitivity
Is the sharp increase of sensitivity of post-synaptic membranes to a chemical transmitter after denervation
A compensatory change
yh idk either man
What happens in the brain during recovery
Brain is able to reduce and reorganise by forming new synaptic connections close to the area of damage
Secondary neural pathways that would not typically be used to carry out certain functions are ‘unmasked’ to enable functioning to continue
Process is supported by a number of structural changes
What are the structural changes that occur during brain recovery
Axon sprouting - new nerve endings grow and connect with undamaged areas
Reformation of blood vessels
Recruitment of homologous (similar) areas - on the opposite hemisphere to do specific tasks, e.g. if Broca’s area was damaged then an area on the right might take over
What is increased brain stimulation as functional recovery of the brain after trauma: an example of plasticity
If neurons are damaged, neighbouring neurons are also affected (works the same for the hemispheres)
Therefore you need to simulate the undamaged neighbouring neurons or healthy hemisphere to aid plasticity
After trauma this can happen very quickly (spontaneous recovery) and then it slows down
What is Elanor Maguire et al’s 2000 study on plasticity
Studied the brains of London taxi drivers using an MRI and found significantly more grey matter in the posterior hippocampus in the matched control group
This part is associated w development of spatial and navigational skills in humans and other animals
As part of their training London Cabbies must take a complex test called ‘the knowledge’ which assesses their recall of the city streets and possible routes
Longer they had been doing job, more pronounced the structural difference was (+ve correlation)
that was long
CALL DOCTOR DOFFENSHMIRTZ
What is the Draganski et al 2006 support for plasticity
Imaged the brains of medical students 3 months b4 and after their final exams
Learning-induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex presumably as a result of the exam
What did Mechelli et al. 2004 do in support for plasticity
Found larger parietal cortex in the brains of people who were bilingual compared to matched monolingual controls
What is the Tajiri et al 2013 research into functional recovery
Provided evidnece for the role of stem cells in recovery from brain injury
They randomly assigned rats with traumatic brain injury to 1 or 2 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 after the brain injury, brains of stem cell rats showed 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
Was not case with control group
What is a +ve evaluation of neuroplacitity as practical application
Understanding plasticity has contributed to the field of neuro-rehabilitation
Following illness or injury to the brain, spontaneous recovery tends to slow down after a number of weeks, so physical therapy may be required
-Including movement therapy and electrical stimulation to counter the deficits and/or cognitive function
-Shows brain has ability to fix itself
What is a -ve evaluation about negative plasticity
Brain’s ability to require itself can have maladaptive behavioural consequences
Prolonged drug use has been shown to result in poorer cognitive function as well as increased risk of dementia (Medina et al 2007)
60-80% of amputees have been known to develop phantom limb syndrome - they experience sensations in the missing limb)
so what if u got a missing fuckin leg u try n walk, face plant into the concrete and just go oh yh shi i forgot again
These sensations are unpleasant, painful and are thought to be due to cortical reorganisation in the somatosensory cortex (Ramachandran & Hirstein 1998)
well u cant call psych names boring thats 4 sure
What is a +ve evaluation about age and plasticity
Brain has a greater propensity for reorganisation in childhood, as it is constantly adapting to new experiences and learning
Bezzola et al 2012 = demonstrated how 40 hrs of golf training produced changes in the neural representation of movement in participants aged 40-60
Using fMRI researches observed reduced motor cortex activity in novice golfers than controls, suggesting more efficient neural representations after training
yh
idk
me neither
ok
i just told avani i need to poo in psych
imma go poo now
What is +ve support for plasticity with animal studies
Hubel and Wiesel 1963
Sewing one eye of a kitten shit and analysing the brain’s cortical responses
Was found that the area of visual cortex associated w shut eye was not idle but continued to process info from the open eye
WHY DIDNT THEY JUST GIVE EM MF BLIDNFOLDS
