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Improved Anatomical Specificity of Non-invasive Neuro-stimulation by High Frequency (5 MHz) Ultrasound.

Li GF, Zhao HX, Zhou H, Yan F, Wang JY, Xu CX, Wang CZ, Niu LL, Meng L, Wu S, Zhang HL, Qiu WB, Zheng HR - Sci Rep (2016)

Bottom Line: Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects.Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation.It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.

ABSTRACT
Low frequency ultrasound (<1 MHz) has been demonstrated to be a promising approach for non-invasive neuro-stimulation. However, the focal width is limited to be half centimeter scale. Minimizing the stimulation region with higher frequency ultrasound will provide a great opportunity to expand its application. This study first time examines the feasibility of using high frequency (5 MHz) ultrasound to achieve neuro-stimulation in brain, and verifies the anatomical specificity of neuro-stimulation in vivo. 1 MHz and 5 MHz ultrasound stimulation were evaluated in the same group of mice. Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects. Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation. The equivalent diameter (ED) of the stimulation region with 5 MHz ultrasound (0.29 ± 0.08 mm) is significantly smaller than that with 1 MHz (0.83 ± 0.11 mm). The response latency of 5 MHz ultrasound (45 ± 31 ms) is also shorter than that of 1 MHz ultrasound (208 ± 111 ms). Consequently, high frequency (5 MHz) ultrasound can successfully activate the brain circuits in mice. It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner.

No MeSH data available.


Related in: MedlinePlus

Comparisons of educed parameters from EMG evoked by 5 MHz and 1 MHz ultrasound stimuli.(a) Two fitted curves were formed by piecewise cubic interpolation from two groups of circle dots set and square dots set, respectively. Each of the circle dots represents the means (n = 6 stimuli) of peak EMG amplitudes evoked by 5 MHz ultrasound at a site, while that of the square dots by 1 MHz. (b) Comparison of the mean values (n = 5 mice) of ED5 and ED1 measured along X Axis and Y Axis. (c) Comparison of the success rate of the EMG signals (n = 5 mice) evoked by 5 MHz and 1 MHz ultrasound at the stimulation regions which are 0, 0.3, and 0.6 mm from the reference point, respectively. (d) Comparison of the mean latency of EMG response to 5 MHz and 1 MHz stimuli at the stimulation regions which are 0 and 0.3 mm from the reference point(L5-0 means latency of 5 MHz at 0 mm site, L1-0.3 means latency of 1 MHz at 0.3 mm site). All of the error bars stand for standard deviations.
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f5: Comparisons of educed parameters from EMG evoked by 5 MHz and 1 MHz ultrasound stimuli.(a) Two fitted curves were formed by piecewise cubic interpolation from two groups of circle dots set and square dots set, respectively. Each of the circle dots represents the means (n = 6 stimuli) of peak EMG amplitudes evoked by 5 MHz ultrasound at a site, while that of the square dots by 1 MHz. (b) Comparison of the mean values (n = 5 mice) of ED5 and ED1 measured along X Axis and Y Axis. (c) Comparison of the success rate of the EMG signals (n = 5 mice) evoked by 5 MHz and 1 MHz ultrasound at the stimulation regions which are 0, 0.3, and 0.6 mm from the reference point, respectively. (d) Comparison of the mean latency of EMG response to 5 MHz and 1 MHz stimuli at the stimulation regions which are 0 and 0.3 mm from the reference point(L5-0 means latency of 5 MHz at 0 mm site, L1-0.3 means latency of 1 MHz at 0.3 mm site). All of the error bars stand for standard deviations.

Mentions: We have made a quantitative comparison of the anatomical specificity of brain stimulated by 1 MHz and 5 MHz ultrasound. Figure 5a shows the stimulation profile of 1 MHz and 5 MHz ultrasound with equivalent diameter (ED) values (n = 6). The stimulation profiles are demonstrated by two fitted curves. One curve was fitted by the points calculated from the normalized peak EMG amplitude of 1 MHz ultrasound, the other curve was from that of 5 MHz. These curves were fitted by piecewise cubic interpolation. The horizontal axis value stands for the stimulation sites along Y axis. Obviously, the 5 MHz curve has sharper and narrower shape than that of 1 MHz. It can be measured that ED5 (ED5 stands for the ED value of 5 MHz ultrasound) value is 0.4 mm and ED1 (ED1 stands for the ED value of 1 MHz ultrasound) value is 0.91 mm. To investigate the total values of ED1 and ED5, statistic data of five mice are plotted on Fig. 5b. Along X axis, ED5 is 0.29 ± 0.08 mm, ED1 is 0.83 ± 0.11 mm, they are statistically different from each other (Paired-sample t-test, t = −11.854, 4 d.f., p < 0.001). Along Y axis, ED5 is 0.40 ± 0.14 mm, ED1 is 0.91 ± 0.21 mm, they are also statistically different from each other (Paired-sample t-test, t = −3.3424, 4 d.f., p < 0.05). It can be clearly concluded that the ED5 value is quite smaller than ED1. In other words, the anatomical specificity is improved by stimulated with 5 MHz ultrasound, as compared with 1 MHz.


Improved Anatomical Specificity of Non-invasive Neuro-stimulation by High Frequency (5 MHz) Ultrasound.

Li GF, Zhao HX, Zhou H, Yan F, Wang JY, Xu CX, Wang CZ, Niu LL, Meng L, Wu S, Zhang HL, Qiu WB, Zheng HR - Sci Rep (2016)

Comparisons of educed parameters from EMG evoked by 5 MHz and 1 MHz ultrasound stimuli.(a) Two fitted curves were formed by piecewise cubic interpolation from two groups of circle dots set and square dots set, respectively. Each of the circle dots represents the means (n = 6 stimuli) of peak EMG amplitudes evoked by 5 MHz ultrasound at a site, while that of the square dots by 1 MHz. (b) Comparison of the mean values (n = 5 mice) of ED5 and ED1 measured along X Axis and Y Axis. (c) Comparison of the success rate of the EMG signals (n = 5 mice) evoked by 5 MHz and 1 MHz ultrasound at the stimulation regions which are 0, 0.3, and 0.6 mm from the reference point, respectively. (d) Comparison of the mean latency of EMG response to 5 MHz and 1 MHz stimuli at the stimulation regions which are 0 and 0.3 mm from the reference point(L5-0 means latency of 5 MHz at 0 mm site, L1-0.3 means latency of 1 MHz at 0.3 mm site). All of the error bars stand for standard deviations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837374&req=5

f5: Comparisons of educed parameters from EMG evoked by 5 MHz and 1 MHz ultrasound stimuli.(a) Two fitted curves were formed by piecewise cubic interpolation from two groups of circle dots set and square dots set, respectively. Each of the circle dots represents the means (n = 6 stimuli) of peak EMG amplitudes evoked by 5 MHz ultrasound at a site, while that of the square dots by 1 MHz. (b) Comparison of the mean values (n = 5 mice) of ED5 and ED1 measured along X Axis and Y Axis. (c) Comparison of the success rate of the EMG signals (n = 5 mice) evoked by 5 MHz and 1 MHz ultrasound at the stimulation regions which are 0, 0.3, and 0.6 mm from the reference point, respectively. (d) Comparison of the mean latency of EMG response to 5 MHz and 1 MHz stimuli at the stimulation regions which are 0 and 0.3 mm from the reference point(L5-0 means latency of 5 MHz at 0 mm site, L1-0.3 means latency of 1 MHz at 0.3 mm site). All of the error bars stand for standard deviations.
Mentions: We have made a quantitative comparison of the anatomical specificity of brain stimulated by 1 MHz and 5 MHz ultrasound. Figure 5a shows the stimulation profile of 1 MHz and 5 MHz ultrasound with equivalent diameter (ED) values (n = 6). The stimulation profiles are demonstrated by two fitted curves. One curve was fitted by the points calculated from the normalized peak EMG amplitude of 1 MHz ultrasound, the other curve was from that of 5 MHz. These curves were fitted by piecewise cubic interpolation. The horizontal axis value stands for the stimulation sites along Y axis. Obviously, the 5 MHz curve has sharper and narrower shape than that of 1 MHz. It can be measured that ED5 (ED5 stands for the ED value of 5 MHz ultrasound) value is 0.4 mm and ED1 (ED1 stands for the ED value of 1 MHz ultrasound) value is 0.91 mm. To investigate the total values of ED1 and ED5, statistic data of five mice are plotted on Fig. 5b. Along X axis, ED5 is 0.29 ± 0.08 mm, ED1 is 0.83 ± 0.11 mm, they are statistically different from each other (Paired-sample t-test, t = −11.854, 4 d.f., p < 0.001). Along Y axis, ED5 is 0.40 ± 0.14 mm, ED1 is 0.91 ± 0.21 mm, they are also statistically different from each other (Paired-sample t-test, t = −3.3424, 4 d.f., p < 0.05). It can be clearly concluded that the ED5 value is quite smaller than ED1. In other words, the anatomical specificity is improved by stimulated with 5 MHz ultrasound, as compared with 1 MHz.

Bottom Line: Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects.Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation.It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.

ABSTRACT
Low frequency ultrasound (<1 MHz) has been demonstrated to be a promising approach for non-invasive neuro-stimulation. However, the focal width is limited to be half centimeter scale. Minimizing the stimulation region with higher frequency ultrasound will provide a great opportunity to expand its application. This study first time examines the feasibility of using high frequency (5 MHz) ultrasound to achieve neuro-stimulation in brain, and verifies the anatomical specificity of neuro-stimulation in vivo. 1 MHz and 5 MHz ultrasound stimulation were evaluated in the same group of mice. Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects. Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation. The equivalent diameter (ED) of the stimulation region with 5 MHz ultrasound (0.29 ± 0.08 mm) is significantly smaller than that with 1 MHz (0.83 ± 0.11 mm). The response latency of 5 MHz ultrasound (45 ± 31 ms) is also shorter than that of 1 MHz ultrasound (208 ± 111 ms). Consequently, high frequency (5 MHz) ultrasound can successfully activate the brain circuits in mice. It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner.

No MeSH data available.


Related in: MedlinePlus