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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

Effect of the sequence order and of the initial network conditions on the average synaptic weight Cav at t = 128 s as a function of stimulation intensity K. (A)Cav-values at t = 128 s obtained by the RVS CR stimulation. (B)Cav-values at t = 128 s obtained by the SVS-100 CR stimulation. The Cav(t = 128 s) values in Figure 2 are the reference results and represented by the solid lines in this Figure. The dashed-dotted lines show the result for a simulation with the same initial network conditions as used to obtain the reference results but for another randomly chosen sequence order. The dotted lines represent the obtained Cav-values at t = 128 s for a simulation with the same sequence order as used to obtain the reference results, but for other initial network conditions.
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Figure 3: Effect of the sequence order and of the initial network conditions on the average synaptic weight Cav at t = 128 s as a function of stimulation intensity K. (A)Cav-values at t = 128 s obtained by the RVS CR stimulation. (B)Cav-values at t = 128 s obtained by the SVS-100 CR stimulation. The Cav(t = 128 s) values in Figure 2 are the reference results and represented by the solid lines in this Figure. The dashed-dotted lines show the result for a simulation with the same initial network conditions as used to obtain the reference results but for another randomly chosen sequence order. The dotted lines represent the obtained Cav-values at t = 128 s for a simulation with the same sequence order as used to obtain the reference results, but for other initial network conditions.

Mentions: To investigate whether this observed improvement by the SVS CR stimulation is just a coincidence, we have also changed the sequence order or the initial network conditions. Figure 3A shows that by applying another RVS order to the same initial network or by applying the initial sequence order to a network with different initial conditions, different long-lasting Cav-values were obtained. Only for the weakest stimulation intensity, K = 0.10, the RVS algorithm caused similar long-lasting Cav-values. For other stimulation intensities, it suggests that the effect of the RVS CR stimulation depends on the sequence order used and on the initial network conditions. As follows from Figure 3B, the success of the SVS-100 CR stimulation depends less strongly on the exact sequence order and the initial network conditions and the SVS-100 CR stimulation results in a smaller Cav-value than the RVS CR stimulation, over a wide range of stimulation intensities K continuing the superiority of this method.


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

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

Effect of the sequence order and of the initial network conditions on the average synaptic weight Cav at t = 128 s as a function of stimulation intensity K. (A)Cav-values at t = 128 s obtained by the RVS CR stimulation. (B)Cav-values at t = 128 s obtained by the SVS-100 CR stimulation. The Cav(t = 128 s) values in Figure 2 are the reference results and represented by the solid lines in this Figure. The dashed-dotted lines show the result for a simulation with the same initial network conditions as used to obtain the reference results but for another randomly chosen sequence order. The dotted lines represent the obtained Cav-values at t = 128 s for a simulation with the same sequence order as used to obtain the reference results, but for other initial network conditions.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Effect of the sequence order and of the initial network conditions on the average synaptic weight Cav at t = 128 s as a function of stimulation intensity K. (A)Cav-values at t = 128 s obtained by the RVS CR stimulation. (B)Cav-values at t = 128 s obtained by the SVS-100 CR stimulation. The Cav(t = 128 s) values in Figure 2 are the reference results and represented by the solid lines in this Figure. The dashed-dotted lines show the result for a simulation with the same initial network conditions as used to obtain the reference results but for another randomly chosen sequence order. The dotted lines represent the obtained Cav-values at t = 128 s for a simulation with the same sequence order as used to obtain the reference results, but for other initial network conditions.
Mentions: To investigate whether this observed improvement by the SVS CR stimulation is just a coincidence, we have also changed the sequence order or the initial network conditions. Figure 3A shows that by applying another RVS order to the same initial network or by applying the initial sequence order to a network with different initial conditions, different long-lasting Cav-values were obtained. Only for the weakest stimulation intensity, K = 0.10, the RVS algorithm caused similar long-lasting Cav-values. For other stimulation intensities, it suggests that the effect of the RVS CR stimulation depends on the sequence order used and on the initial network conditions. As follows from Figure 3B, the success of the SVS-100 CR stimulation depends less strongly on the exact sequence order and the initial network conditions and the SVS-100 CR stimulation results in a smaller Cav-value than the RVS CR stimulation, over a wide range of stimulation intensities K continuing the superiority of this method.

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