State-dependent neurovascular modulation induced by transcranial ultrasound stimulation
Hang Song, Ruoyu Chen, Liyuan Ren, Junfeng Sun, Shanbao Tong
Medical & Biological Engineering & Computing 2025 · 10.1007/s11517-025-03290-5
Abstract
Previous studies reported baseline state-dependent effects on neural and hemodynamic responses to transcranial ultrasound stimulation. However, due to neurovascular coupling, neither neural nor hemodynamic baseline alone can fully explain the ultrasound-induced responses. In this study, using a general linear model, we aimed to investigate the roles of both neural and hemodynamic baseline status as well as their interactions in ultrasound-induced responses. Thirty Sprague-Dawley rats were randomly assigned to Hypoxia, Hyperoxia, and Normoxia groups. The baseline states were altered by changing the oxygen concentrations. Micro-electrode and laser speckle contrast imaging were used to record local field potentials and cerebral blood flow during resting, before, and after ultrasound stimulation, respectively. We found that baseline neural activity played a positive role in neural response (Coefficient = 0.634, t = 1.748, p = 0.096, ηp2 = 0.133), but a negative role in hemodynamic response (Coefficient = - 0.060, t = - 1.996, p = 0.060, ηp2 = 0.166). Baseline hemodynamic activity also had a significantly negative correlation with the hemodynamic response (Coefficient = - 0.760, t = - 3.947, p < 0.001, ηp2 = 0.438). This study enriched our understanding of state-dependent effects underlying the neurovascular activation by ultrasound stimulation.
Abstract via europepmc.
Exposures
Exposure 1: TUS at S1 under hypoxia, hyperoxia and normoxia
Target: primary somatosensory cortex — “S1”
Device: Olympus / Panametrics · Olympus NDT · V318-SU ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 500 | ✓✓✓ |
| Pulse duration (ms) | 0.4 | ✓✓✓⚑ |
| Pulse repetition frequency (Hz) | 1,500 | ✓✓✓ |
| Duty cycle (%) | not reportedpulse duration × PRF gives 60% | ⚑ |
| Sonication duration (s) | 1 | ✓✓✓⚑ |
| 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 | |
| Isppa, domain unspecified (W/cm²) | 8.69 | ✓✓✓⚑ |
5 min of stimulation consisting of 1-s sonications (tone burst duration 0.4 ms, PRF 1.5 kHz) with an interstimulus interval of 4 s, delivered through a 3-mm plexiglass collimator.
Flags from extraction
n_subjects— 30 rats enrolled; 6 were used in a preliminary experiment and 24 (8 per group) in the formal experiment.n_sessions_per_subject— A single 5-min TUS session per rat is implied by the protocol but the number of sessions is not stated.exposures[0].unspecified_domain.isppa_w_cm2— Isppa given without stating the medium; a hydrophone measured the field with the collimator attached.exposures[0].timing.duty_cycle_pct— Duty cycle is mentioned but its value is not stated.exposures[0].timing.pulse_duration_ms— Burst rule: TBD 0.4 ms taken as the pulse; sonication duration (SD) 1 s is the train; 'ISI = 4 s' interpretation as gap between sonications is assumed from the protocol.exposures[0].timing.sonication_duration_s— Nested structure: 1-s sonications repeated across a 5-min session with a 4-s ISI.
Notes: Hypoxia, hyperoxia and normoxia were used to change baseline state; all three groups received the same TUS.