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Induction of Long-term Depression-like Plasticity by Pairings of Motor Imagination and Peripheral Electrical Stimulation.

Jochumsen M, Signal N, Nedergaard RW, Taylor D, Haavik H, Niazi IK - Front Hum Neurosci (2015)

Bottom Line: Long-term depression (LTD) and long-term potentiation (LTP)-like plasticity are models of synaptic plasticity which have been associated with memory and learning.A significant decrease (P = 0.001) in the excitability of the cortical projection of TA was observed when the afferent volley from the ES of the tibial nerve (TN) reached the cortex at the onset of motor imagination based on the CNV.Nor was a significant effect found when ES of the TN was applied independent of imagined movement (P = 0.45).

View Article: PubMed Central - PubMed

Affiliation: Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University Denmark Aalborg, Denmark.

ABSTRACT
Long-term depression (LTD) and long-term potentiation (LTP)-like plasticity are models of synaptic plasticity which have been associated with memory and learning. The induction of LTD and LTP-like plasticity, using different stimulation protocols, has been proposed as a means of addressing abnormalities in cortical excitability associated with conditions such as focal hand dystonia and stroke. The aim of this study was to investigate whether the excitability of the cortical projections to the tibialis anterior (TA) muscle could be decreased when dorsiflexion of the ankle joint was imagined and paired with peripheral electrical stimulation (ES) of the nerve supplying the antagonist soleus muscle. The effect of stimulus timing was evaluated by comparing paired stimulation timed to reach the cortex before, at and after the onset of imagined movement. Fourteen healthy subjects participated in six experimental sessions held on non-consecutive days. The timing of stimulation delivery was determined offline based on the contingent negative variation (CNV) of electroencephalography brain data obtained during imagined dorsiflexion. Afferent stimulation was provided via a single pulse ES to the peripheral nerve paired, based on the CNV, with motor imagination of ankle dorsiflexion. A significant decrease (P = 0.001) in the excitability of the cortical projection of TA was observed when the afferent volley from the ES of the tibial nerve (TN) reached the cortex at the onset of motor imagination based on the CNV. When TN stimulation was delivered before (P = 0.62), or after (P = 0.23) imagined movement onset there was no significant effect. Nor was a significant effect found when ES of the TN was applied independent of imagined movement (P = 0.45). Therefore, the excitability of the cortical projection to a muscle can be inhibited when ES of the nerve supplying the antagonist muscle is precisely paired with the onset of imagined movement.

No MeSH data available.


Related in: MedlinePlus

The averaged (across subjects) MEPmax is shown for each of the main interventions (Before, At and and After the onset of motor imagination) and control experiments (CPN stimulation at the onset of motor imagination and TN alone). 0% change with respect to the baseline means no change from the pre- to post-intervention measurements. ‘∗’ indicates a significant difference in the MEPmax from the pre- to post-intervention measurements.
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Figure 3: The averaged (across subjects) MEPmax is shown for each of the main interventions (Before, At and and After the onset of motor imagination) and control experiments (CPN stimulation at the onset of motor imagination and TN alone). 0% change with respect to the baseline means no change from the pre- to post-intervention measurements. ‘∗’ indicates a significant difference in the MEPmax from the pre- to post-intervention measurements.

Mentions: The results are summarized in the following three subsections and in Figures 2 and 3. The ES of TN was timed according to peak negativity of the CNV recorded in each subject’s baseline session. On average, ES was delivered 705.45 ± 76.93 ms prior to the onset of the task (before motor imagination), 56 ± 289 ms prior to the onset of the task (at motor imagination) and 450.45 ± 103.08 ms after the onset of the task (after motor imagination). There were no significant differences in the size of the MEPs in the pre-intervention measurements across sessions 2–6 [F(8,104) = 1.02; P = 0.43].


Induction of Long-term Depression-like Plasticity by Pairings of Motor Imagination and Peripheral Electrical Stimulation.

Jochumsen M, Signal N, Nedergaard RW, Taylor D, Haavik H, Niazi IK - Front Hum Neurosci (2015)

The averaged (across subjects) MEPmax is shown for each of the main interventions (Before, At and and After the onset of motor imagination) and control experiments (CPN stimulation at the onset of motor imagination and TN alone). 0% change with respect to the baseline means no change from the pre- to post-intervention measurements. ‘∗’ indicates a significant difference in the MEPmax from the pre- to post-intervention measurements.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664642&req=5

Figure 3: The averaged (across subjects) MEPmax is shown for each of the main interventions (Before, At and and After the onset of motor imagination) and control experiments (CPN stimulation at the onset of motor imagination and TN alone). 0% change with respect to the baseline means no change from the pre- to post-intervention measurements. ‘∗’ indicates a significant difference in the MEPmax from the pre- to post-intervention measurements.
Mentions: The results are summarized in the following three subsections and in Figures 2 and 3. The ES of TN was timed according to peak negativity of the CNV recorded in each subject’s baseline session. On average, ES was delivered 705.45 ± 76.93 ms prior to the onset of the task (before motor imagination), 56 ± 289 ms prior to the onset of the task (at motor imagination) and 450.45 ± 103.08 ms after the onset of the task (after motor imagination). There were no significant differences in the size of the MEPs in the pre-intervention measurements across sessions 2–6 [F(8,104) = 1.02; P = 0.43].

Bottom Line: Long-term depression (LTD) and long-term potentiation (LTP)-like plasticity are models of synaptic plasticity which have been associated with memory and learning.A significant decrease (P = 0.001) in the excitability of the cortical projection of TA was observed when the afferent volley from the ES of the tibial nerve (TN) reached the cortex at the onset of motor imagination based on the CNV.Nor was a significant effect found when ES of the TN was applied independent of imagined movement (P = 0.45).

View Article: PubMed Central - PubMed

Affiliation: Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University Denmark Aalborg, Denmark.

ABSTRACT
Long-term depression (LTD) and long-term potentiation (LTP)-like plasticity are models of synaptic plasticity which have been associated with memory and learning. The induction of LTD and LTP-like plasticity, using different stimulation protocols, has been proposed as a means of addressing abnormalities in cortical excitability associated with conditions such as focal hand dystonia and stroke. The aim of this study was to investigate whether the excitability of the cortical projections to the tibialis anterior (TA) muscle could be decreased when dorsiflexion of the ankle joint was imagined and paired with peripheral electrical stimulation (ES) of the nerve supplying the antagonist soleus muscle. The effect of stimulus timing was evaluated by comparing paired stimulation timed to reach the cortex before, at and after the onset of imagined movement. Fourteen healthy subjects participated in six experimental sessions held on non-consecutive days. The timing of stimulation delivery was determined offline based on the contingent negative variation (CNV) of electroencephalography brain data obtained during imagined dorsiflexion. Afferent stimulation was provided via a single pulse ES to the peripheral nerve paired, based on the CNV, with motor imagination of ankle dorsiflexion. A significant decrease (P = 0.001) in the excitability of the cortical projection of TA was observed when the afferent volley from the ES of the tibial nerve (TN) reached the cortex at the onset of motor imagination based on the CNV. When TN stimulation was delivered before (P = 0.62), or after (P = 0.23) imagined movement onset there was no significant effect. Nor was a significant effect found when ES of the TN was applied independent of imagined movement (P = 0.45). Therefore, the excitability of the cortical projection to a muscle can be inhibited when ES of the nerve supplying the antagonist muscle is precisely paired with the onset of imagined movement.

No MeSH data available.


Related in: MedlinePlus