Effect of low-intensity transcranial ultrasound stimulation on theta and gamma oscillations in the mouse hippocampal CA1
Zhen Li, Rong Chen, Dachuan Liu, Xizhe Wang, Wei Yuan
Frontiers in Psychiatry 2023 · 10.3389/fpsyt.2023.1151351
Abstract
Previous studies have demonstrated that low-intensity transcranial ultrasound stimulation (TUS) can eliminate hippocampal neural activity. However, until now, it has remained unclear how ultrasound modulates theta and gamma oscillations in the hippocampus under different behavioral states. In this study, we used ultrasound to stimulate the CA1 in mice in anesthesia, awake and running states, and we simultaneously recorded the local field potential of the stimulation location. We analyzed the power spectrum, phase-amplitude coupling (PAC) of theta and gamma oscillations, and their relationship with ultrasound intensity. The results showed that (i) TUS significantly enhanced the absolute power of theta and gamma oscillations under anesthesia and in the awake state. (ii) The PAC strength between theta and gamma oscillations is significantly enhanced under the anesthesia and awake states but is weakened under the running state with TUS. (iii) Under anesthesia, the relative power of theta decreases and that of gamma increases as ultrasound intensity increases, and the result under the awake state is opposite that under the anesthesia state. (iv) The PAC index between theta and gamma increases as ultrasound intensity increases under the anesthesia and awake states. The above results demonstrate that TUS can modulate theta and gamma oscillations in the CA1 and that the modulation effect depends on behavioral states. Our study provides guidance for the application of ultrasound in modulating hippocampal function.
Abstract via europepmc.
Exposures
Exposure 1: TUS of CA1, anaesthesia, awake and running states
Target: CA1 — “CA1”
Device: not reported
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 2,250 | ✓✓✓ |
| Pulse duration (ms) | not reportedimplied by duty cycle ÷ PRF: 0.5 ms (not stated by the paper) | ⚑ |
| Pulse repetition frequency (Hz) | 1,000 | ✓✓✓ |
| Duty cycle (%) | 50 | ✓✓✓ |
| Sonication duration (s) | 0.4 | ✓✓✓ |
| Free-field pressure (kPa) | not reported | |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | not reported | |
| In-situ estimate | not reported | |
| In-situ pressure (kPa) | not reported | |
| In-situ Isppa (W/cm²) | not reported | |
| In-situ Ispta (W/cm²) | not reported | |
| Pressure, domain unspecified (kPa) | 150, 300, 450, 600, 750swept | ✓✓✓⚑ |
| Isppa, domain unspecified (W/cm²) | 0.75, 3, 6.75, 12, 18.75swept | ✓✓✓ |
16 trials per animal; each trial 400 ms stimulation duration at 1 kHz PRF and 50% duty cycle. Intensity 0.45 MPa for the theta/gamma comparison across states; five intensities for the intensity series.
Flags from extraction
n_subjects— 42 mice in total: 21 for state comparison, 21 for the intensity series (7 per state in each).exposures[0].timing.pulse_duration_ms— Pulse duration not stated; 400 ms is the stimulation duration (train), not the pulse.exposures[0].unspecified_domain.pressure_kpa— Intensities given in MPa without stating whether water or in situ; converted 0.15-0.75 MPa to kPa. Focused beam at about 45 degrees into the brain.exposures[0].device.family— Transducer not described; refers to previous papers.anaesthesia— 0.5% isoflurane in the anaesthesia group; awake and running groups head-fixed without anaesthesia.