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.