Transcranial Focused Ultrasound Stimulation Improves Neurorehabilitation after Middle Cerebral Artery Occlusion in Mice
Jixian Wang, Guofeng Li, Lidong Deng, Muyassar Mamtilahun, Lu Jiang, Weibao Qiu, Hairong Zheng, Junfeng Sun, Qing Xie, Guo-Yuan Yang
Aging and disease 2021, 12, 50 · 10.14336/ad.2020.0623
Abstract
Transcranial focused ultrasound stimulation (tFUS) regulates neural activity in different brain regions in humans and animals. However, the role of ultrasound stimulation in modulating neural activity and promoting neurorehabilitation in the ischemic brain is largely unknown. In the present study, we explored the effect of tFUS on neurological rehabilitation and the underlying mechanism. Adult male ICR mice (n=42) underwent transient middle cerebral artery occlusion. One week after brain ischemia, low frequency (0.5 MHz) tFUS was applied to stimulate the ischemic hemisphere of mice for 7 consecutive days (10 minutes daily). Brain infarct volume, neurobehavioral tests, microglia activation, IL-10 and IL-10R levels were further assessed for up to 14 days. We found that the brain infarct volume was significantly reduced in the tFUS treated mice compared to that in the non-treated mice ( p p p <0.05). We concluded that tFUS served as a unique technique to promote neurorehabilitation after brain ischemia by promoting microglia polarization and further regulating IL-10 signaling in the ischemic brain.
Abstract via europepmc.
Exposures
Exposure 1: tFUS to ischemic hemisphere after MCAO
Target: cerebral cortex — “ischemic hemisphere (selected region of the cortex)”
Device: custom-built · Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 500 | ✓✓✓ |
| Pulse duration (ms) | 0.5 | ✓✓✓ |
| Pulse repetition frequency (Hz) | 1,000 | ✓✓✓ |
| Duty cycle (%) | not reportedpulse duration × PRF gives 50% | ⚑ |
| Sonication duration (s) | 0.3 | ✓✓✓ |
| 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) | 0.12 | ✓✓✓⚑ |
tFUS was delivered with a portable ultrasound stimulation system to the selected cortical region of the ischemic hemisphere; the stimulation sequence used a toneburst-duration (TBD), pulse repetition frequency (PRF), sonication duration (SD) and 2.7 s inter-stimuli interval (ISI) as illustrated in Fig. 2D. Beginning 7 days after MCAO, ultrasound stimulation was performed for 10 minutes per day over 7 consecutive days, totaling 360 trials of ultrasound stimulation.
Flags from extraction
exposures[0].unspecified_domain.isppa_w_cm2— Paper does not state whether the reported Isppa (120 mW/cm2) is a free-field or in-situ value; placed in unspecified_domain.exposures[0].timing.duty_cycle_pct— Duty cycle is not stated explicitly; arithmetic from pulse duration (0.5 ms) and PRF (1000 Hz) would suggest 50% but this is not computed per instructions.sham_type— Only an untreated MCAO-alone control group is described; no sham ultrasound (e.g. inactive transducer) arm was used.