Excerpt: "Tyler and colleagues believed that low intensity ultrasound may modulate neuronal excitability in 2 ways:
1) mechanical stress might change the viscoelastic properties of lipid bilayers and
2) mechano-sensitive transmembrane proteins may modulate receptor channel gating kinetics (refs).
Recent observations have indicated that LIFU could activate voltage-gated sodium and calcium channels, thereby eliciting action potentials and synaptic transmission. In fact, these results ratify Tyler ‘s second hypothesis (refs).
Similarly, a model has been proposed which incorporates the effect of acoustic radiation force on cells as a result of changes in membrane capacitance (ref). On the other hand, radiation forces play a crucial role in endothelial nitric oxide synthesis, which in turn regulates the functions of ion channels."
Sound (sound waves): Molecules pushing their neighbors and then returning to original position.
Hitting a drum membrane sets its molecules in motion (back and forth) and these set the air molecules in motion (back and forth); the latter push on to their neighbors and make them move in the same pattern. If these the molecules of our ear drum, we will perceive sound.
Sound is transmitted for instance through air, water or solids.
One back and forth corresponds to one cycle.
Cycles in the unit of time is the frequency (how frequent are the cycles).
Number of cycles per second corresponds to Hz.
Human audible range of sound: 20 Hz to 20.000Hz
Sound beyond (=ultra) the human audible sound is called “ultrasound”.
Medical ultrasound devices operate from 20.000Hz to several GHz.
Focused ultrasound is in the news for #depression & #parkinsons trials, but how does it work? http://www.fusfoundation.org/for-patients/how-it-works …
The first clinical trial aimed to treat #depression using focused ultrasound is underway! http://www.fusfoundation.org/news/129-press-room/1664-first-depression-clinical-trial-with-focused-ultrasound-begins …
Kimberly's back on her bike after focused ultrasound treatment for Parkinson's dyskinesia http://www.fusfoundation.org/news/1650-parkinson-s-patient-no-longer-just-spinning-her-wheels …
Note: Low-intensity focused ultrasound (LIFU) is used for neuromodulation, while high-intensity focused ultrasound (HIFU) for cell ablation via heating.
A Review of Low-Intensity Transcranial Focused Ultrasound for Clinical Applications
A. Bystritsky, A. S. Korb,
Curr Behav Neurosci Rep (2015) 2:60 66
Image-Guided Transcranial Focused Ultrasound Stimulates Human Primary Somatosensory Cortex
Wonhye Lee, Hyungmin Kim, Yujin Jung, In-Uk Song, Yong An Chung & Seung-Schik Yoo
Scientific Reports 5, Article number: 8743 (2015)
Transcranial Focused Ultrasound to the Thalamus Alters Anesthesia Time in Rats.
Yoo S-S, Kim H, Min B-K, Eric Franck SP.
Neuroreport. 2011;22(15):783-787. doi:10.1097/WNR.0b013e32834b2957.
FUS Imagine Project: Imaging of blood circulation in brain microvasculature with focused ultrasound (ultrafast Doppler)- Correlation with EEG
Video at this page http://fultrasound.eu shows imaging during rat whisker stimulation and during seizure propagation in epilepsy. Leader M. Tanter comments that it is very difficult or impossible to obtain these results with MRI.
EN/FR https://erc.europa.eu/projects-figures/stories/babys-brain-never-seen (Project funded by European Research Council)
"Tanter's novel technique is based on sonography, a method that relies on the generation of images by the bouncing of ultrasound waves. Commonly used by doctors - for instance during pregnancy - it had never been applied to neuroscience before as traditional ultrasound only allowed to image the blood flow in large blood vessels. To see the subtle neuronal activity of the smaller vessels of the brain, where the blood flow is less intense, an increased imaging sensitivity was indispensable. It has been achieved by Prof. Tanter’s team by combining ultrafast imaging rates and dedicated processing algorithms."
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