Effect of pulsed transcranial ultrasound stimulation at different number of tone-burst on cortico-muscular coupling
Ping Xie, Sa Zhou, Xingran Wang, Yibo Wang, Yi Yuan
BMC Neuroscience 2018 · 10.1186/s12868-018-0462-8
Abstract
Background Pulsed transcranial ultrasound stimulation (pTUS) can modulate the neuronal activity of motor cortex and elicit muscle contractions. Cortico-muscular coupling (CMC) can serve as a tool to identify interaction between the oscillatory activity of the motor cortex and effector muscle. This research aims to explore the neuromodulatory effect of low-intensity, pTUS with different number of tone burst to neural circuit of motor-control system by analyzing the coupling relationship between motor cortex and tail muscle in mouse. The motor cortex of mice was stimulated by pulsed transcranial ultrasound with different number of tone bursts (NTB = 100 150 200 250 300). The local field potentials (LFPs) in tail motor cortex and electromyography (EMG) in tail muscles were recorded simultaneously during pTUS. The change of integral coupling strength between cortex and muscle was evaluated by mutual information (MI). The directional information interaction between them were analyzed by transfer entropy (TE). Results Almost all of the MI and TE values were significantly increased by pTUS. The results of MI showed that the CMC was significantly enhanced with the increase of NTB. The TE results showed the coupling strength of CMC in descending direction (from LFPs to EMG) was significantly higher than that in ascending direction (from EMG to LFPs) after stimulation. Furthermore, compared to NTB = 100, the CMC in ascending direction were significantly enhanced when NTB = 250, 300, and CMC in descending direction were significantly enhanced when NTB = 200, 250, 300. Conclusion These results confirm that the CMC between motor cortex and the tail muscles in mouse could be altered by pTUS. And by increasing the NTB (i.e. sonication duration), the coupling strength within the cortico-muscular circuit could be increased, which might further influence the motor function of mice. It demonstrates that, using MI and TE method, the CMC could be used for quantitatively evaluating the effect of pTUS with different NTBs, which might provide a new insight into the effect of pTUS neuromodulation in motor cortex.
Abstract via europepmc.
Exposures
Exposure 1: pTUS to tail motor cortex, NTB 100-300
Target: motor cortex — “tail motor cortex”
Device: Olympus / Panametrics · Olympus · V301-SU ✓
| 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) | not reported | ⚑ |
| 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) | 1.1 | ✓✓✓⚑ |
Pulsed TUS with 250 acoustic cycles per pulse (NC), PRF 1 kHz, inter-trial interval 3.6 s; the sonication duration was changed with the number of tone bursts (NTB 100, 150, 200, 250, 300). Pulse duration, duty cycle and sonication duration in time units are not stated.
Flags from extraction
exposures[0].unspecified_domain.isppa_w_cm2— Paper gives 'acoustic intensity (AI)' 1.10 W/cm2 without saying whether spatial-peak pulse-average or temporal-average, or measured where; placed in isppa as the nearest field.exposures[0].timing.pulse_duration_ms— Only 250 cycles per pulse at 500 kHz is stated; no pulse duration in time units given.exposures[0].timing.sonication_duration_s— Sonication duration varies with NTB (100-300 tone bursts) but is not stated in seconds.anaesthesia— Mice were anaesthetised for surgery and recorded after the anaesthesia effect was over; recorded as awake.exposures[0].timing.protocol_description— 'Number of tone bursts' (NTB) appears to count pulses; meaning of 'tone burst' not fully resolved.