Transcranial ultrasound stimulation at the peak-phase of theta-cycles in the hippocampus improve memory performance

Xie, Zhenyu; Dong, Shuxun; Zhang, Yiyao; Yuan, Yi

doi:10.1016/j.neuroimage.2023.120423

Cited by 4 publications

(5 citation statements)

References 70 publications

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“…Results of recent experimental studies are in line with some of the predictions made in this work. In particular, bursts of stimulation phased-locked to the peak of the slow rhythm were found to increase PAC compared to baseline and to stimulation provided at the trough of the slow rhythm [25, 26]. These could correspond to purely excitatory pulses acting through the mechanism presented in section 2.1.1 (see figure 2A), or to pulses with excitatory and inhibitory components acting through the mechanism presented in section 2.1.2 (see figure 2B) where phase-alignment with the peak of the fast oscillations happens through entrainment.…”

Section: Discussionmentioning

confidence: 99%

“…PAC was also found to be abnormal in various neurological disorders -see [11] for a review. In Parkinson's disease (PD), coupling between the beta phase (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) and gamma amplitude in the motor cortex is exaggerated compared to patients with dystonia and patients with epilepsy, both at rest and during movement [12]. Elevated PAC was reported in patients with PD off dopaminergic medication compared to patients on medication, as well as compared to humans without a movement disorder [13].…”

Section: Introductionmentioning

confidence: 99%

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How to design optimal brain stimulation to modulate phase-amplitude coupling?

Duchet,

Bogacz

2024

Preprint

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Objective. Phase-amplitude coupling (PAC), the coupling of the amplitude of a faster brain rhythm to the phase of a slower brain rhythm, plays a significant role in brain activity and has been implicated in various neurological disorders. For example, in Parkinson's disease, PAC between the beta (13-30 Hz) and gamma (50-200 Hz) rhythms in the motor cortex is exaggerated, while in Alzheimer's disease, PAC between the theta (4-8 Hz) and gamma rhythms is diminished. Modulating PAC (i.e. reducing or enhancing PAC) using brain stimulation could therefore open new therapeutic avenues. However, while it has been previously reported that phase-locked stimulation can increase PAC, it is unclear what the optimal stimulation strategy to modulate PAC might be. Here, we provide a theoretical framework to narrow down the experimental optimisation of stimulation aimed at modulating PAC, which would otherwise rely on trial and error. Approach. We make analytical predictions using a Stuart-Landau model, and confirm these predictions in a more realistic model of coupled neural populations. Main results. Our framework specifies the critical Fourier coefficients of the stimulation waveform which should be tuned to optimally modulate PAC. Depending on the characteristics of the amplitude response curve of the fast population, these components may include the slow frequency, the fast frequency, combinations of these, as well as their harmonics. We also show that the optimal balance of energy between these Fourier components depends on the relative strength of the endogenous slow and fast rhythms, and that the alignment of fast components with the fast rhythm should change throughout the slow cycle. Furthermore, we identify the conditions requiring to phase-lock stimulation to the fast and/or slow rhythms. Significance. Together, our theoretical framework lays the foundation for guiding the development of innovative and more effective brain stimulation aimed at modulating PAC for therapeutic benefit.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

How to design optimal brain stimulation to modulate phase-amplitude coupling?

Duchet,

Bogacz

2024

Preprint

View full text Add to dashboard Cite

show abstract

“…Results of recent experimental studies are in line with some of the predictions made in this work. In particular, bursts of stimulation phased-locked to the peak of the slow rhythm were found to increase PAC compared to baseline and to stimulation provided at the trough of the slow rhythm [ 25 , 26 ]. These could correspond to purely excitatory pulses acting through the mechanism presented in section 2.1.1 (see figure 2(A) ), or to pulses with excitatory and inhibitory components acting through the mechanism presented in section 2.1.2 (see figure 2(B) ) where phase-alignment with the peak of the fast oscillations happens through entrainment.…”

Section: Discussionmentioning

confidence: 99%

“…PAC was also found to be abnormal in various neurological disorders-see [12] for a review. In Parkinson's disease (PD), coupling between the beta phase (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) and gamma amplitude in the motor cortex is exaggerated compared to patients with dystonia and patients with epilepsy, both at rest and during movement [13]. Elevated PAC was reported in patients with PD off dopaminergic medication compared to patients on medication, as well as compared to humans without a movement disorder [14].…”

Section: Introductionmentioning

confidence: 99%

“…A notable exception is the work by Salimpour and colleagues, which showed that phase-locking motor cortical electrical stimulation to the peak of the beta rhythm increased beta-gamma PAC in humans compared to baseline, and compared to stimulation phase-locked to the trough of the beta rhythm [ 25 ]. Similarly, phase-locking hippocampal transcranial ultrasound stimulation to the peak of the theta rhythm increased theta-gamma PAC in rats [ 26 ]. Nevertheless, it is unclear what the optimal stimulation strategy to enhance or decrease PAC might be.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

How to design optimal brain stimulation to modulate phase-amplitude coupling?

Duchet,

Bogacz

2024

J. Neural Eng.

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Objective. Phase-amplitude coupling (PAC), the coupling of the amplitude of a faster brain rhythm to the phase of a slower brain rhythm, plays a significant role in brain activity and has been implicated in various neurological disorders. For example, in Parkinson’s disease, PAC between the beta (13–30 Hz) and gamma (30–100 Hz) rhythms in the motor cortex is exaggerated, while in Alzheimer’s disease, PAC between the theta (4–8 Hz) and gamma rhythms is diminished. Modulating PAC (i.e. reducing or enhancing PAC) using brain stimulation could therefore open new therapeutic avenues. However, while it has been previously reported that phase-locked stimulation can increase PAC, it is unclear what the optimal stimulation strategy to modulate PAC might be. Here, we provide a theoretical framework to narrow down the experimental optimisation of stimulation aimed at modulating PAC, which would otherwise rely on trial and error. Approach. We make analytical predictions using a Stuart–Landau model, and confirm these predictions in a more realistic model of coupled neural populations. Main results. Our framework specifies the critical Fourier coefficients of the stimulation waveform which should be tuned to optimally modulate PAC. Depending on the characteristics of the amplitude response curve of the fast population, these components may include the slow frequency, the fast frequency, combinations of these, as well as their harmonics. We also show that the optimal balance of energy between these Fourier components depends on the relative strength of the endogenous slow and fast rhythms, and that the alignment of fast components with the fast rhythm should change throughout the slow cycle. Furthermore, we identify the conditions requiring to phase-lock stimulation to the fast and/or slow rhythms. Significance. Together, our theoretical framework lays the foundation for guiding the development of innovative and more effective brain stimulation aimed at modulating PAC for therapeutic benefit.

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