UNIVERSITY OF JYVÄSKYLÄ
Motor Skill Learning and Brain Plasticity
Janne Avela & Susanne Kumpulainen
Neuromuscular Research Center, Department of Biology of Physical ActivityUniversity of Jyvaskyla, Finland
Brain Plasticity
Brain's ability to change at any time and age – for better or worse• Plasticity of the brain is important for learning, memory,
motor adaptation and recovery from brain injury
Rapid plastic changes:• Activity dependent synaptic plasticity (Jacobs & Donaghue 1991)
• Long-term potentiation (LTP)• Long term depression (LTD)
• Activation of existing but silent synapses (Liao et al. 1999)
Morphological plastic changes (Kleim et al. 1996):• Synaptogenesis • Neurogenesis
Brain Plasticity Changes Induced by Long -term Physical Exercise
� Regular physical exercise� Global benefits to the brain:
• Increases brain plasticity(for review see Kramer and Erickson 2007)
• Improves neurocognitive functions
� Different types of physical exercise� Experience-specific adaptation in the
corticospinal system (for review see Adkins et al. 2006)
Magnetic stimuli produce a motor evoked potential ( MEP) in the target muscle
EMG
Trancranial magnetic stimulation
to study the cortical motor areas targeting long finger flexor and extensor muscles in subjects learning a one-handed, five-finger exercise on the piano.2 hours x 5 days
• Changes in the excitability and reorganisation in the representation of the corticomotor projection to the hand in a group of elite athletes
• Absence of any such changes in a group of social players suggests that long-term reinforcement and constructive practice of skilled motor tasks can lead to functional plasticity of the corticomotor projection
Brain Plasticity
Brain's ability to change at any age – for better or worse• Plasticity of the brain is important for learning, memory,
motor adaptation and recovery from brain injury
Rapid plastic changes:• Activity dependent synaptic plasticity (Jacobs & Donaghue 1991)
• Long-term potentiation (LTP)• Long term depression (LTD)
• Activation of existing but silent synapses (Liao et al. 1999)
Morphological plastic changes (Kleim et al. 1996):• Synaptogenesis ?• Neurogenesis
Paired Associative Stimulation (PAS)
Activity -dependent SynapticPlasticity
Ability of sensory and motor cortices to dynamically reorganize
“‘Coincident activity in two connected neurons leads to strengthening of their connection”
Hebb 1949
• Potentiation takes place if the postsynaptic neuron fires an action potential after the excitatory postsynaptic potential is induced by the presynaptic neuron
Long-term potentiation (LTP)
Paired Associative Stimulation (PAS)
(Stefan K, Kunesch E, Cohen LG, Benecke R, Classen J. (2000) Brain. 2000 Mar;123 Pt 3:572-84)
PAS is a non-invasive method developed to induce bidirectional changes in the excitability of the cortical projections to the target muscle
Based on Hebb’s law
An electrical stimulation of peripheral somatosensory afferents paired with TMS over the contralateral motor cortex
“Early motor learning = LTP-like mechanisms are used to increase performance after short-term motor practice.”
“Late motor learning = supported by synaptogenesis, which leads to enhanced corticospinal and intracortical
recruitment.”
PAS reacts on both, LTP-like mechanisms and synaptogenesis
To investigate the effects of skill and endurancetraining background on motor cortex plasticity
Skill group:
• 11 Dancers
• 2 FigureSkaters
• 2 Gymnasts
Endurance group:
• 8 Cross-Country Skiers
• 4 Orienteerers
• 3 Runners
Subject Data
Skill group Endurance group
Subjects (f/m) 15 (12/3) 15 (10/5)
Age 23 26
Height 166 cm 172 cm
Weight 60 kg 62 kg
Output 51 % 54 %
Training years 14 12
Training/week 8 h 10 h
Competitors 10 15
Methods - Protocol
PAS-intervention
POST
* TMS x10- Passive muscle
* SLR x10- 20 % 0f MVC
PRE
* MVC x 3* SEP
* TMS x10- Passive muscle
* SLR x10- 20 % 0f MVC
Results – Motor Evoked Potentials
SKILL
ENDURANCE
PRE-MEP
POST-MEP
176%
93%
0%
50%
100%
150%
200%
250%
300%
Skill Endurance
Results – Short Latency Stretch Reflex
40 ms
0.4
mV
BaselinePost
SKILL
ENDURANCE
0
0.5
1
1.5
2
Skill Endurance
No
rm
alized
SLR
Baseline
Post
SKILL ENDURANCE
� Significant LTP-like plasticity in skill group but not in endurance group
�Different training induced adaptations in the motor cortex
• Skill training → increased synapse number →
greater potential for plasticity (Rosenkranz et al. 2007)
• Endurance training → best possible efficiency →
automatic movements (Doyon and Benali 2005) →
subcortical loops → Reduced use of motor cortex
Discussion
Practical implications
For Brain Rehabilitation :• Versatile skill training for
synaptogenesis• Endurance training for
angiogenesis
Combination!!!!
Practical implicationsFor Sport:• Versatile skill training• To create motor learning potential• In order to learn sport spesific technigue