plasticity and functional recovery of the brain after trauma Flashcards
what does brain plasticity include?
-ability to change overtime
-synaptic pruning= as we rarely use connections they are delete and frequently used ones are strengthened
what is maguire et al study?
- studied the brains of taxi drivers
-big volume of grey matter in posterior hippocampus than in matched control group
-associated with navigational skills
-taxi drivers take the knowledge test (of routes )
what did maguire et al find?
-learning experience alters structure of the brain
-the more the taxi drivers were in the job the more positive correlation
what did Draganski et al find similar to maguire?
-draganski imaged the brains of medical students 3 months before and after final exams
- learning induced changes were seen in posterior hippocampus and parietal cortex bc of learning
what is functional recovery after brain trauma?
-following injury areas of the brain can adpat and compensate for damage
-healthy brain areas can often take over functions
-some may require rehabilitaitve therpay to further their recovery
what happens in the brain during recovery?
-forms new synaptic connections
-secondary neural pathways are activated to help carry out functions
what are the structural changes occuring in the brain?
-axonal sprouting= growth of new nerve endings which connect to undamaged nerve cells to form new pathways
-denervation supersensitivty= when axons that do a similar job become aroused to compensate for the ones that were lost e.g but can be negative consequence of oversnesiitivty to msgs like pain
-recruitment of homologous area of opposite sides of the brain
e.g brocas area on left side getting damage so right equivelent side would carry out functions
after some time the function may go back to the left side
what is a negative of plasticity?
(negative plasticity)
-brains adaption to prolonged durg use leads to poorer cognitive function in later life and increased risk of dementia
-60-80% of amputees have been known to develop phantom limb syndrome(the contuined feeling of sensations in missing limb as if its still there)
usually unpleasent and painful
-brains ability to adapt to damage therefore not always beneficial
strenghts of plasticity?
(age and plasticty)
-may be a life long ability
-ladina bezzola et al demonsatted how 40 hrs of golf produced changes in neural reprsenations in ppl age 40-60
-FMRI showed reduced motor cortex activity in novice golfers comapred to control grp
-more efficient neural represeantions after training
- can happen throughout lifespan
evaluating seasonal brain changes
-there evidence that the SCN shrinks in all animals during spring expands in autum
-BUT mainly done only on animal studies
-humans may be different
strength of functional recovery?
(real world app)
-contributed to neurorehab
-understanding axonal growth allows for new therapies to be tried
-e.g stroke therpaies where the prsn repeatdly uses affected area of the body whilst unaffected body part is restrained
-useful for medical interventions
weaknesses of functional recovery?
(cognitive reserve)
-scheinder et al = the more time people had spent in ED with a brain injury the more chance of disability free recovery
-those achieveing DFR had spent more than 16 yrs in ED (40%)
-comapred to ab 10% with less than 12 yrs in ED
-so those with less time in ED may not recieve a full recovery
(small samples)
-banerjee treated ppl with total anetrior circulation stoke with stem cells
-all ps recovered
-only 5 ps and no control grp- too small
