Salk scientist wins NIH grant for new technique to precisely target specific cells using sound waves

Salk Associate Professor Sreekanth Chalasani has been awarded a grant from the National Institutes of Health's (NIH) Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative for developing a way to selectively activate brain, heart, muscle and other cells using ultrasonic waves, which could be a boon to neuroscience research as well as medicine.

Chalasani will receive over $1 million for the first year of the award to expand his groundbreaking technology into mammalian cells. If it works in humans, such a technology could be used for deep brain stimulation--a common treatment in Parkinson's and depression. It could also be used outside of the brain to act as a pacemaker for a heart or to produce insulin from pancreatic cells.

"The Chalasani lab developed a revolutionary way to precisely target specific cells in a living organism using sound waves," says Salk President Elizabeth Blackburn. "With support from the BRAIN Initiative, Sreekanth will be able to expand his trailblazing science which could lead to many exciting applications in research and medicine."

Chalasani's new technique, which he calls sonogenetics, has some similarities to the burgeoning use of light (optogenetics) to activate cells in order to better understand the brain, but is less invasive. This method-which uses the same type of waves used in medical sonograms-may have additional advantages over optogenetics particularly when it comes to adapting the technology to human therapeutics. Chalasani first demonstrated the technique on nematodes in 2015, showing that low-intensity ultrasound waves propagating into the worms caused a membrane ion channel called TRP-4 to open and activate cells. His team also added the TRP-4 channel and successfully activated neurons that don't usually react to ultrasound. With the new grant, Chalsani is developing technology to deliver focused ultrasonic waves to particular regions of the mammalian brain and is also exploring additional ion channels that could be targeted with ultrasound.

"I am very grateful for the support to pursue this research and see whether this technique can work in mammals and translate to humans for medical benefits," says Chalasani, who is collaborating with additional Salk labs as well as with the University of California, San Diego on the effort.

"In only three years we've already seen exciting new advances in neuroscience research come out of the BRAIN Initiative," says Walter J. Koroshetz, MD, director of NIH's National Institute of Neurological Disorders and Stroke. "There are very few effective cures for neurological and neuropsychiatric disorders. By pushing the boundaries of fundamental neuroscience research, NIH BRAIN Initiative scientists are providing the insights researchers will need to develop 21st century treatments."