The mechanical nature of sound waves may spark proteins which are sensitive to Ultrasound. This idea engaged a team of scientists at the Salk Institute for Biological Studies at La Jolla, U.S., searching for a protein that imparts ultrasound sensitivity to targeted cells.
A library of proteins which may be Ultrasound sensitive has been prepared. To their surprise, the protein TRPA1 has been found to be Ultrasound sensitive and confers it to multiple cell types in mammals, such as neurons, fibroblasts, muscle and insulin-secreting cells.
Using a gene therapy approach, they added the genes coding for the human TRPA1 protein to a specific group of neurons in the brains of living mice and subsequently administered Ultrasound in the mice and observed that only neurons with the TRPA1 genes were activated.
The existing methods for triggering brain cells are; deep brain stimulation, pacemakers or insulin pumps in humans. All these devices require surgery and implants and are associated with life risk. Also, the existing electromagnetic approaches are limiting in precision and cannot affect deep regions of the brain.
This new research can potentially replace deep brain stimulation, pacemakers or insulin pumps in humans and minimise the risk to life. If one can deliver protein to the relevant cells, one can manipulate them from outside the body without surgery.
It can be targeted with high precision and potentially affect the brain’s deep regions selectively. These findings have been published in the journal Nature Communication, February 2022.
A brief historical development
The effect of Ultrasound on nerve-cell activity was first demonstrated in the beginning of the nineteenth century by experimenting on a frog. The researchers had placed a frog leg and heart into a salt solution and passed ultrasound waves through the bath. They observed the muscles twitch.
In 1958, the influence of Ultrasound on the animal’s neurological system was demonstrated by experiments on cats. Then, it took about 50 years to provide the mechanism underlying those experiments by Tyler and colleagues.
In an experiment with cultured mouse hippocampal slices, it has been found that Ultrasound influences nerve impulses by activating voltage-gated sodium and calcium channels. In 2010, the stimulation of brain cells in the motor cortices of anaesthetised mice using Ultrasound was successfully demonstrated.
After a few years, experimenters at INSERM — France’s biomedical-research agency — reproduced the effect in brain areas that control eye movements in conscious monkeys. In 2014, Tyler’s group applied the technique to humans, stimulating the somatosensory cortex. This brain area processes tactile information, which was further extended to the primary visual cortex, which controls sight, by Seung-Schik Yoo and his co-workers from the Catholic University of Korea, in 2016.
The medical college of SGT University, Gurugram, is well equipped with advanced ultrasound tools for diagenesis and treatments. Hopefully, the new findings will prove to be a boon in future for triggering brain and heart cells from outside and serving human beings by minimising the life risk.
The Faculty of Science, SGT University, is one of the best private University in Delhi NCR for science courses. The faculty has five departments: Department of Physics, Department of Chemistry, Department of Mathematics, Department of Forensic Science, and Department of Environmental Science. The Faculty of Science offers 12 courses – 2 Undergraduate, 5 Post Graduate, and 5 PhDs.
Prof (Dr.) Ram Chhavi Sharma
Department of Physics
Faculty of Science