Ultrasound shown to exert remote control of brain circuits


November 20, 2008

In a twist on nontraditional uses of ultrasound, a group of neuroscientists at Arizona State University has developed pulsed ultrasound techniques that can remotely stimulate brain circuit activity. Their findings, published in the Oct. 29 issue of the journal Public Library of Science (PLoS) One, provide insights into how low-power ultrasound can be harnessed for the noninvasive neurostimulation of brain circuits and offers the potential for new treatments of brain disorders and disease.  

While it might be hard to imagine the day where doctors could treat post traumatic stress disorders, traumatic brain injury and even Alzheimer’s disease with the flip of a switch, most of us have in fact experienced some of ultrasound’s numerous applications in our daily lives. For example, ultrasound has been used in fetal and other diagnostic medical imaging, ultrasonic teeth cleaning, physiotherapies, or surgical ablation. Ultrasound also provides a multitude of other non-medical uses, including pharmaceutical manufacturing, food processing, nondestructive materials testing, sonar, communications, oceanography and acoustic mapping.   Download Full Image

“Studies of ultrasound and its interactions with biological tissues have a rich history dating back to the late 1920s,” lead investigator William “Jamie” Tyler points out. “Several research groups have, for more than a half-century, demonstrated that ultrasound can produce changes in excitable tissues, such as nerve and/or muscle, but detailed studies in neurons at the cellular level have been lacking.” 

“We were able to unravel how ultrasound can stimulate the electrical activity of neurons by optically monitoring the activity of neuronal circuits, while we simultaneously propagated low-intensity, low-frequency ultrasound through brain tissues,” says Tyler, assistant professor of neurobiology and bioimaging in the School of Life Sciences in the College of Liberal Arts and Sciences.  

Led by Tyler, the ASU research group discovered that remotely delivered low intensity, low frequency ultrasound (LILFU) increased the activity of voltage-gated sodium and calcium channels in a manner sufficient to trigger action potentials and the release of neurotransmitter from synapses. Since these processes are fundamental to the transfer of information among neurons, the authors pose that this type of ultrasound provides a powerful new tool for modulating the activity of neural circuits.  

“Many of the stimulation methods used by neuroscientists require the use and implantation of stimulating electrodes, requiring direct contact with nervous tissue or the introduction of exogenous proteins, such as those used for the light-activation of neurons,” Tyler explains. 

The search for new types of noninvasive neurostimulation methods led them to revisit ultrasound.  

“We were quite surprised to find that ultrasound at power levels lower than those typically used in routine diagnostic medical imaging procedures could produce an increase in the activity of neurons while higher power levels produced very little effect on their activity,” Tyler says. 

Other neuroscientists and engineers have also been rapidly developing new neurostimulation methods for controlling nervous system activity and several approaches show promise for the treatment of a wide variety of nervous system disorders. For example, Deep Brain Stimulation (DBS) and Vagal Nerve Stimulation (VNS) have been shown to be effective in the management of psychiatric disorders such as depression, bipolar disorders, post-traumatic stress disorder, and drug addition, as well as for therapies of neurological diseases such as Parkinson’s disease, Alzheimer’s disease, Tourette Syndrome, epilepsy, dystonia, stuttering, tinnitus, recovery of cognitive and motor function following stroke, and chronic pain. Up until now, these two techniques have captured the attention of physicians and scientists; however, these therapies still pose risks to patients because they require the surgical implantation of stimulating electrodes. Thus, these types of therapies are often only available to patients presenting the worst of prognoses.  

One prior stumbling block to using ultrasound noninvasively in the brain has been the skull. However, the acoustic frequencies utilized by Tyler and his colleagues to construct their pulsed ultrasound waveforms, overlap with a frequency range where optimal energy gains are achieved between transcranial transmission and brain absorption of ultrasound – which allows the ultrasound to penetrate bone and yet prevent damage to the soft tissues. Their findings are supported by other studies examining the potential of high-intensity focused ultrasound for ablating brain tissues, where it was shown that low-frequency ultrasound could be focused through human skulls.  

When asked about the potential of using his groups’ methods to remotely control brain activity, Tyler says: “One might be able to envision potential applications ranging from medical interventions to use in video gaming or the creation of artificial memories along the lines of Arnold Schwarzenegger’s character in ‘Total Recall.’ Imagine taking a vacation without actually going anywhere?

“Obviously, we need to conduct further research and development, but one of the most exhilarating prospects is that low intensity, low frequency ultrasound permit deep-brain stimulation procedures without requiring exogenous proteins or surgically implanted medical devices,” he adds.  

Tyler and the other ASU researchers will now focus on further characterization of the influence of ultrasound on intact brain circuits and translational research, taking low intensity ultrasound from the lab into pre-clinical trials and treatment of neurological diseases.

Margaret Coulombe

Director, Executive Communications, Office of the University Provost

480-965-8045

Waissi joins ASU Global as associate vice president


November 20, 2008

Gary Waissi, former dean of the School of Global Management and Leadership, has joined ASU Global, the Office of the Vice President for Global Engagement, as an associate vice president, effective Nov. 10.

Waissi will work closely with the Office of the Provost and academic units on global academic programming, assisting with development of specialized programs to enhance the number and quality of international students and scholars coming to ASU, thereby assisting in the area of strategic global partnerships. He will work to identify ASU strengths in order to integrate those capacities across units and help to develop and customize academic programs in support of the challenges and strategic global outcomes defined by ASU Global and the university’s broader institutional priorities. Download Full Image

“I am pleased to join the ASU Global team at a time when the university is both positioning itself as a highly competitive international institution, and at the same time strengthening the global culture across ASU’s campuses,” says Waissi. “I look forward to building on relationships I’ve established in order to continue advancing the university’s reputation as a global focus for academic excellence, cross-cultural understanding and economic development and entrepreneurship.”

Waissi came to ASU in 2006 from the University of Michigan – Dearborn, where he served as dean of the School of Management and, earlier, chair of the Department of Management and as a faculty member. Waissi has worked projects for the University of Michigan’s William Davidson Institute; the International Business School in Tashkent, Uzbekistan; the Banking Institute, L’vov, Ukraine; and the School of Finance and Banking, Kigali, Rwanda. Prior to coming to Michigan, he worked for Philipp Holzmann AG in Frankfurt am Main, Germany and in Nigeria.

“Expanding ASU’s reach to the international student and scholar community is a vital component of our effort to bring greater global awareness to ASU campuses,” says Anthony “Bud” Rock, ASU’s vice president for global engagement. “Gary understands this well, and has direct experience in developing these types of programs. He will work with academic units on a full range of creative ways to connect this international community with ASU’s priority programs.”

Waissi speaks five languages – English, Finnish, German, Russian and Swedish – and earned his doctorate in engineering, with an emphasis on operations research, from the University of Michigan, Ann Arbor.

He is a member of the Arizona Consular Corps, and in Michigan he served as the Honorary Consul of Finland.