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Differences in dopaminergic modulation to motor cortical plasticity between Parkinson's disease and multiple system atrophy.

Kawashima S, Ueki Y, Mima T, Fukuyama H, Ojika K, Matsukawa N - PLoS ONE (2013)

Bottom Line: Dopamine modulates the synaptic plasticity in the primary motor cortex (M1).The dopamine replacement therapy in PD, but not in MSA-P effectively restored the PAS-induced MEP increase.This suggests that not the existence of dopamine itself but the activation of cortico-striatal circuit might play an important role for cortical plasticity in the human M1.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Neuroscience, Nagoya City University Graduate School of Medical Science, Nagoya, Japan.

ABSTRACT
Dopamine modulates the synaptic plasticity in the primary motor cortex (M1). To evaluate whether the functioning of the cortico-striatal circuit is necessary for this modulation, we applied a paired associative stimulation (PAS) protocol that comprised an electric stimulus to the right median nerve at the wrist and subsequent transcranial magnetic stimulation of the left M1, to 10 patients with Parkinson's disease (PD) and 10 with multiple system atrophy of the parkinsonian type (MSA-P) with and without dopamine replacement therapy (-on/off). To investigate the M1 function, motor-evoked potentials (MEPs) were measured before and after the PAS. In both patient groups without medication, the PAS protocol failed to increase the averaged amplitude of MEPs. The dopamine replacement therapy in PD, but not in MSA-P effectively restored the PAS-induced MEP increase. This suggests that not the existence of dopamine itself but the activation of cortico-striatal circuit might play an important role for cortical plasticity in the human M1.

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Related in: MedlinePlus

Effect of dopaminergic medication on PAS-induced modulation of the MEP amplitude with PD-on and-off.In PD patients, the average MEP amplitude in the right APB was significantly elevated after dopaminergic medication (*P<0.05).
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pone-0062515-g001: Effect of dopaminergic medication on PAS-induced modulation of the MEP amplitude with PD-on and-off.In PD patients, the average MEP amplitude in the right APB was significantly elevated after dopaminergic medication (*P<0.05).

Mentions: Looking at the between-subjects effects, the three-factor ANOVA showed no significant main effects for disease (P = 0.13), treatment (P = 0.20) and time (P = 0.36). There were significant time × treatment × disease (*P = 0.006), time × treatment (*P = 0.032), time × disease (*P<0.001) interactions, but not significant disease × treatment interaction (P = 0.11). Post hoc t-tests revealed the significant increase of MEP amplitude after PAS only for the PD patients with medication (*P = 0.03) (Figure 1). In contrast, there were no significant change of MEP amplitude after PAS in PD patients without medication (P = 0.86) and in MSA patients both with (P = 0.2) and without medication (P = 0.86) (Figure 2).


Differences in dopaminergic modulation to motor cortical plasticity between Parkinson's disease and multiple system atrophy.

Kawashima S, Ueki Y, Mima T, Fukuyama H, Ojika K, Matsukawa N - PLoS ONE (2013)

Effect of dopaminergic medication on PAS-induced modulation of the MEP amplitude with PD-on and-off.In PD patients, the average MEP amplitude in the right APB was significantly elevated after dopaminergic medication (*P<0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3643922&req=5

pone-0062515-g001: Effect of dopaminergic medication on PAS-induced modulation of the MEP amplitude with PD-on and-off.In PD patients, the average MEP amplitude in the right APB was significantly elevated after dopaminergic medication (*P<0.05).
Mentions: Looking at the between-subjects effects, the three-factor ANOVA showed no significant main effects for disease (P = 0.13), treatment (P = 0.20) and time (P = 0.36). There were significant time × treatment × disease (*P = 0.006), time × treatment (*P = 0.032), time × disease (*P<0.001) interactions, but not significant disease × treatment interaction (P = 0.11). Post hoc t-tests revealed the significant increase of MEP amplitude after PAS only for the PD patients with medication (*P = 0.03) (Figure 1). In contrast, there were no significant change of MEP amplitude after PAS in PD patients without medication (P = 0.86) and in MSA patients both with (P = 0.2) and without medication (P = 0.86) (Figure 2).

Bottom Line: Dopamine modulates the synaptic plasticity in the primary motor cortex (M1).The dopamine replacement therapy in PD, but not in MSA-P effectively restored the PAS-induced MEP increase.This suggests that not the existence of dopamine itself but the activation of cortico-striatal circuit might play an important role for cortical plasticity in the human M1.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Neuroscience, Nagoya City University Graduate School of Medical Science, Nagoya, Japan.

ABSTRACT
Dopamine modulates the synaptic plasticity in the primary motor cortex (M1). To evaluate whether the functioning of the cortico-striatal circuit is necessary for this modulation, we applied a paired associative stimulation (PAS) protocol that comprised an electric stimulus to the right median nerve at the wrist and subsequent transcranial magnetic stimulation of the left M1, to 10 patients with Parkinson's disease (PD) and 10 with multiple system atrophy of the parkinsonian type (MSA-P) with and without dopamine replacement therapy (-on/off). To investigate the M1 function, motor-evoked potentials (MEPs) were measured before and after the PAS. In both patient groups without medication, the PAS protocol failed to increase the averaged amplitude of MEPs. The dopamine replacement therapy in PD, but not in MSA-P effectively restored the PAS-induced MEP increase. This suggests that not the existence of dopamine itself but the activation of cortico-striatal circuit might play an important role for cortical plasticity in the human M1.

Show MeSH
Related in: MedlinePlus