logo ped kur suu maj 2010

8/17/2019 Logo Ped Kur Suu Maj 2010

1/21

Plasticity of the nervous system

- “an old concept with a new meaning” –a brief introduction …

Jörgen Borg MD PhD

Department of linical !ciences" #eha$ilitation Medicine

%arolins&a 'nstitutet" Danderyd (ospital

!toc&holm" !weden


2/21

Plasticity of the nervous system

• fundamental for learning andrelearning - reha$ilitationinterventions

• evolving in parallel with $asicand clinical neuroscience


3/21

“Plasticity”

• Plasticity – the ability to be moulded /shaped ( from )ree& ”plastos” *

• Neuroplasticity

• Brain plasticity

• Peripheral nerve system plasticity


4/21

“Brain plasticity” – introduced $y

• +illiam James ,./0-12*

3 4merican psychologist

and philosopher

• $rain functions are not fi5ed

throughout life ,Principles of

Psychology .12*


5/21

3eurons and their

communication666


6/21

3erve cells visualised

• !antiago #am7n y a8al,.90 –1:/* !panishhistologist" 3o$el laureate12;

• microscopic structure ofnerve cells and synaptic cleft


7/21

!ynapse

• ”!ynapse< from )ree&


8/21

3eurotransmission@modulation

• (enry Dale - identified acetylcholinein 1/

• Atto ?oewi ,.=: –1;* laterdemonstrated its role in the nervous

system

• 3o$el laureates 1:;


9/21

!ynaptic plasticity- “(e$$ian

learning”

• Donald (e$$ ,12/ –1.9*" anadian

psychologist

•“6 66two cells or systems of cells that arerepeatedly active at the same time willtend to $ecome associated" so thatactivity in one facilitates activity in theother6“ ,1/1*


10/21

!ynaptic strength - ?ong Cerm

Potentiation and Depression

• Cer8e ?mo 1;;E synaptic long-lasting@long-termpotentiation @?CP - increase in the synapticstrength of neurons in hippocampus followingelectrical stimulation

• change of postsynaptic cells sensitivity to inputfrom presynaptic cells

•

?CP and ?CD important mechanisms for learningand memory


11/21

3ew synapses

• - in response to e5periences in normal $rain

•- from dendritic and a5onal sproutes in in8ured $rain


12/21

ortical networ&s - in response to

manipulated input to normal brain

• 'n e5perimental animalsE

• Plasticity in visual corte5 – “critical period”

Hubel DH, iesel !N"#$%&ies

• Plasticity in auditory andsomatosensory corte5 'erenich '' and

Bla)e D!


13/21

ortical networ&s - in response to in*ury

in e+perimental animalsE

“!pared regions ad8acent to the infarctand far removed from the infarctundergo functional alterations that aremodified $y $ehavioural e5perience

?ong-range intracortical pathways can

$e rerouted to completely novel

territories” andolph " Nudo,

e.iring of intracortical path.ays after

ischemic in*ury to '#" tro)e" 0&&12345part06748&-489":

• Hand motor map in mon)ey

postin*ury and .ith no training o

.ith training (Nudo , #$$1 'o

Psychiatry:"


14/21

SMA

F

G

3

C'

A

3

Intervention

Cime after 'n8ury : mo ; mo

linical o$servations – reclaiming

function666


15/21

linical recovery and plasticity

• 3umerous studies have descri$ed the recovery curve ofvarious functions in patients with stro&e and CB'

• orrelates with reorganisation of networ&s - asdemonstrated $y an increasing num$er of imaging studies -

since the pioneering studies $y hollet F et al @P>C" ao H etal@fM#' in the 112-ies

• #eorganisation depends on age at in8ury" time since in8uryand interventions


16/21

#eorganisation of motor networ&s early

in life - role of ipsilateral motor corte5

Cwo types of ipsilateral reorganiIation in congenital hemiparesisE

a CM! and fM#' study6 taudt ', ;rodd , ;erloff


17/21

Dynamic changes of networ&s in adults

at various time points after stro&e

Chree phasesE a strongly reduced activationof remaining left languageareas in the acute phase is follo.ed by

an up regulation .ith

recruitment of homologuelanguage ones, .hichcorrelates .ith languageimprovement…

a normaliation of activation isobserved, possibly reflecting

consolidation in thelanguage system"

!aur et al 022;


18/21

@nterventions - Cctivity dependent

• 3umeral studies have

demonstrated reorganisationof $rain activity pattern inresponse to

• 'ntense training of motor and

cognitive tas&s• 'magination of movements

• Functional relevanceconfirmed $y virtual CM!lesions

?ind$erg P) et al6 se-dependent up- and do.n-regulation ofsensorimotor brain circuits in stro)e patients"7 Neurorehabil Neural epair" 0&&1 ul-Cug20#(8:73#9-0%"


19/21

Behind todays concept66

• Huge number of observational and e+perimental studies

• East t.o decades7

• Human brain net.or)s related to sensory-motor" speech-cognitive functions" emotions and “consciousness”

• eorganisation of these net.or)s in response to in8ury andinterventions


20/21

#eferences in Pu$Med 4pril 022

• 3europlasticity 04 0%4 (F$&G after #$$&:

• Brain plasticity 08 191• !ynaptic plasticity #9 &&$

• fM#' and plasticity # 0&%

• P>C and plasticity #%%

• ?earning and plasticity 4 813

• Motor recovery and plasticity 4%$

• Pain and plasticity # 398

• CM! and plasticity 089

• D! and plasticity 13

•

ehabilitation and plasticity # #04


21/21

urrent meaning of $rain plasticity in

reha$ilitation medicine

•Functional improvements after an acKuired $rain in8ury areparalleled $y reorganisation of cere$ral networ&s

• !uch reorganisation is activity driven – new technologies may $esupportive ,also in order to avoid “maladaptive” plasticity*

• Functional imaging will soon $e part of routine functionaldiagnostic set up and used to design individualised interventions,*

logo ped kur suu maj 2010

Documents