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Augmented brain function by coordinated reset stimulation with slowly varying sequences.

Zeitler M, Tass PA - Front Syst Neurosci (2015)

Bottom Line: So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS).In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR.To this end, a sequence is applied many times before randomly switching to the next sequence.

View Article: PubMed Central - PubMed

Affiliation: Research Center Jülich, Institute of Neuroscience and Medicine, Neuromodulation (INM-7) Jülich, Germany.

ABSTRACT
Several brain disorders are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR) stimulation was developed to selectively counteract abnormal neuronal synchrony by desynchronization. For this, phase resetting stimuli are delivered to different subpopulations in a timely coordinated way. In neural networks with spike timing-dependent plasticity CR stimulation may eventually lead to an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and abnormal synchrony. The spatiotemporal sequence by which all stimulation sites are stimulated exactly once is called the stimulation site sequence, or briefly sequence. So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS). In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR. To this end, a sequence is applied many times before randomly switching to the next sequence. This new method is called SVS CR stimulation, i.e., CR with slowly varying sequences. In a neuronal network with strong short-range excitatory and weak long-range inhibitory dynamic couplings SVS CR stimulation turns out to be superior to CR stimulation with fixed sequences or RVS.

No MeSH data available.


Related in: MedlinePlus

Dynamics of the average synaptic weight, Cav, for different stimulation intensities, K. (A) Results of the RVS CR stimulation. (B) Results of the SVS-100 CR stimulation. The initial network is the same for all simulations. The sequence order used for each CR method is constant for all K-values. The CR-on period, represented by the red horizontal bar, starts at t = 0 s and is switched off at t = 64 s (dashed vertical line). During the subsequent 64 s CR-off period, no stimulation is delivered, and Cav evolves spontaneously. cmax = 1 for all simulations.
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Figure 2: Dynamics of the average synaptic weight, Cav, for different stimulation intensities, K. (A) Results of the RVS CR stimulation. (B) Results of the SVS-100 CR stimulation. The initial network is the same for all simulations. The sequence order used for each CR method is constant for all K-values. The CR-on period, represented by the red horizontal bar, starts at t = 0 s and is switched off at t = 64 s (dashed vertical line). During the subsequent 64 s CR-off period, no stimulation is delivered, and Cav evolves spontaneously. cmax = 1 for all simulations.

Mentions: As visualized in Figure 2A the RVS CR stimulation causes a weakening of the average synaptic weight Cav during the CR-on period for all stimulation intensities K. At the end of the subsequent CR-off period, the average synaptic weight is still much weaker than before the CR stimulation was applied, except for the weakest stimulation intensity. Figure 2B then shows how the SVS CR stimulation, delivered to the same initial network, decreases the average synaptic weights even more and causes in general lower long-lasting Cav–values compared to the RVS CR stimulation. Since we are interested in the long-lasting effects of the CR stimulation period, we will concentrate on the values at the end of the CR-off for the remainder of this work.


Augmented brain function by coordinated reset stimulation with slowly varying sequences.

Zeitler M, Tass PA - Front Syst Neurosci (2015)

Dynamics of the average synaptic weight, Cav, for different stimulation intensities, K. (A) Results of the RVS CR stimulation. (B) Results of the SVS-100 CR stimulation. The initial network is the same for all simulations. The sequence order used for each CR method is constant for all K-values. The CR-on period, represented by the red horizontal bar, starts at t = 0 s and is switched off at t = 64 s (dashed vertical line). During the subsequent 64 s CR-off period, no stimulation is delivered, and Cav evolves spontaneously. cmax = 1 for all simulations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4379899&req=5

Figure 2: Dynamics of the average synaptic weight, Cav, for different stimulation intensities, K. (A) Results of the RVS CR stimulation. (B) Results of the SVS-100 CR stimulation. The initial network is the same for all simulations. The sequence order used for each CR method is constant for all K-values. The CR-on period, represented by the red horizontal bar, starts at t = 0 s and is switched off at t = 64 s (dashed vertical line). During the subsequent 64 s CR-off period, no stimulation is delivered, and Cav evolves spontaneously. cmax = 1 for all simulations.
Mentions: As visualized in Figure 2A the RVS CR stimulation causes a weakening of the average synaptic weight Cav during the CR-on period for all stimulation intensities K. At the end of the subsequent CR-off period, the average synaptic weight is still much weaker than before the CR stimulation was applied, except for the weakest stimulation intensity. Figure 2B then shows how the SVS CR stimulation, delivered to the same initial network, decreases the average synaptic weights even more and causes in general lower long-lasting Cav–values compared to the RVS CR stimulation. Since we are interested in the long-lasting effects of the CR stimulation period, we will concentrate on the values at the end of the CR-off for the remainder of this work.

Bottom Line: So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS).In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR.To this end, a sequence is applied many times before randomly switching to the next sequence.

View Article: PubMed Central - PubMed

Affiliation: Research Center Jülich, Institute of Neuroscience and Medicine, Neuromodulation (INM-7) Jülich, Germany.

ABSTRACT
Several brain disorders are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR) stimulation was developed to selectively counteract abnormal neuronal synchrony by desynchronization. For this, phase resetting stimuli are delivered to different subpopulations in a timely coordinated way. In neural networks with spike timing-dependent plasticity CR stimulation may eventually lead to an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and abnormal synchrony. The spatiotemporal sequence by which all stimulation sites are stimulated exactly once is called the stimulation site sequence, or briefly sequence. So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS). In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR. To this end, a sequence is applied many times before randomly switching to the next sequence. This new method is called SVS CR stimulation, i.e., CR with slowly varying sequences. In a neuronal network with strong short-range excitatory and weak long-range inhibitory dynamic couplings SVS CR stimulation turns out to be superior to CR stimulation with fixed sequences or RVS.

No MeSH data available.


Related in: MedlinePlus