Saks to discuss future of forensic science

June 11, 2010

Regents’ Professor Michael">">Michael Saks is a featured speaker at two upcoming events in Lexington, Kentucky, where he will discuss the 2009 national report about the future of forensic science.

On June 15, at the 37th annual Public Defender Education Conference, Saks will address the use of the National Academy of Sciences’ report, “Strengthening Forensic Science in the United States: A Path Forward.” The report, an extensive evaluation of forensic science, was completed by the National Research Council at the request of Congress. Download Full Image

Saks will present “Does Forensic Science Have a New Future?” on June 16 at the Kentucky Bar Association’s 2010 Convention, “Building Blocks of Democracy: Civics, Communities, Access to Justice.” His talk, part of a CLE, will explain some of the major problems the council found with the forensic sciences, highlight some of its recommendations, and discuss its assessment of judicial performance in this area.

Shortly after the report’s release, Saks co-chaired a major conference at the College of Law, “Forensic Science in the 21st Century: The National Academy of Sciences and Beyond,” which was attended by 400 scholars, judges, prosecutors, public defenders, private attorneys, forensic scientists, technicians and lab managers, criminalists and students.

He is a Regents’ Professor of Law and Psychology, and a Faculty Fellow in the College of Law’s Center for Law, Science & Innovation. His research focuses on empirical studies of the legal system, especially decision-making, the behavior of the litigation system, and the law’s use of science. Saks is the fourth most-cited law-and-social-science scholar in the U.S., and has authored approximately 200 articles and books. Courses he has taught include criminal law, evidence, law and science, property and torts.

Janie Magruder, Jane.Magruder">">
(480) 727-9052
Sandra Day O’Connor College of Law

New method offers platform for brain treatment

June 11, 2010

The ability to diagnose and treat brain dysfunction without surgery may rely on a new method of non-invasive brain stimulation using pulsed ultrasound developed by a team of scientists, led by William “Jamie” Tyler, a neuroscientist at Arizona State University. The approach, published in the journal Neuron on June 9, shows that pulsed ultrasound not only stimulates action potentials in intact motor cortex in mice, but it also “elicits motor responses comparable to those only previously achieved with implanted electrodes and related techniques,” said Yusuf Tufail, the lead author from ASU’s School of Life Sciences.

Other techniques such as transcranial magnetic and deep brain stimulation, electroconvulsive shock therapy and transcranial direct current stimulation are used to treat a range of brain dysfunctions, including epilepsy, Parkinson’s disease, chronic pain, coma, dystonia, psychoses and depression. However, most of these approaches suffer from “critical weaknesses,” Tyler said, including requirements for surgery, low-spatial resolution or genetic manipulations. Optogenetics, for example, is one state-of-the-art technology that merges genes from plants and other organisms with the intact brains of animals to offer control of neural circuitry. Download Full Image

“Scientists have known for more than 80 years that ultrasound can influence nerve activity,” Tufail said. “Pioneers in this field transmitted ultrasound into neural tissues prior to stimulation with traditional electrodes that required invasive procedures. Those studies demonstrated that ultrasound pre-treatments could make nerves more or less excitable in response to electrical stimulation.

“In our study, however, we used ultrasound alone to directly stimulate action potentials and drive intact brain activity without doing any kind of surgery.”

“It is fascinating to witness these effects firsthand,” he added. Tufail is one of four doctoral students in ASU’s School of Life Sciences who worked with Tyler on the project. The team also included Alexei Matyushov, a physics undergraduate student in ASU’s Barrett Honors College working with Tyler, and Nathan Baldwin, a doctoral student in bioengineering, and Stephen Helms Tillery, an assistant professor, with ASU’s Ira A. Fulton Schools of Engineering.

"We knew from some of our previous work that ultrasound could directly stimulate action potentials in dishes containing slices of brain tissue,” Tyler said. “Moving to transmit ultrasound through the skin and skull to stimulate the intact brain inside a living animal posed a much greater challenge.”

Despite such challenges, the study shows how ultrasound can be used to stimulate brain circuits with millimeter spatial resolution.

“We’ve come a long way from the observations of Scribonius Largus, a Roman physician in the 1st century A.D. who placed electric torpedo fish on headache sufferers’ foreheads to ease their pain,” Tyler said. “Our method paves the way for using sound waves to study and manipulate brain function, as well as to diagnose and treat its dysfunction.”

In addition to advancing hope for noninvasive treatments of brain injury and disease, the groups’ experiments in deeper subcortical brain circuits also revealed that ultrasound may be useful for modifying cognitive abilities.

"We were surprised to find that ultrasound activated brain waves in the hippocampus known as sharp-wave ripples,” Tufail said. “These brain activity patterns are known to underlie certain behavioral states and the formation of memories.”

The scientists also found that ultrasound stimulated the production of brain-derived neurotrophic factor (BDNF) in the hippocampus – one of the most potent regulators of brain plasticity.

Tyler said the fact that ultrasound can be used to stimulate action potentials, meaningful brain wave activity patterns, and BDNF leads him to believe that, in the future, ultrasound will be useful for enhancing cognitive performance; perhaps even in the treatment of cognitive disabilities such as mental retardation or Alzheimer's disease.

Tyler’s students also have collected data that suggests that repeated exposure to low-intensity ultrasound does not pose a health risk to rodents.

"We examined many aspects of brain health following stimulation and found that low-intensity ultrasound is safe for repeatedly stimulating the brains of mice," said Anna Yoshihiro, a neuroscience doctoral student in ASU’s College of Liberal Arts and Sciences and co-author of the journal article. Yoshihiro works to treat Parkinsonian monkeys and has achieved some early success in treating epileptic seizures in mice using ultrasonic neuromodulation.

Monica Li Tauchmann, Yoshihiro’s contemporary and co-author on the article, recalls the first time the method worked: "I was helping with experiments. We were trying to stimulate the brain of a living mouse with ultrasound. Not a whole lot was happening at first. Then, Dr. Tyler changed some of the ultrasound waveform parameters and the mouse started moving. We spent the rest of that day repeating the stimulation and the mouse was perfectly fine. It recovered from anesthesia as if nothing had happened. I think we were all astonished."

Tyler believes that there are a host of potential applications for ultrasound in brain manipulation. Besides basic science and medical uses, ultrasound represents a core platform around which future brain-machine interfaces can also be designed for gaming, entertainment and communication purposes because of its noninvasive nature.

“Space travel, hand-held computers, the Internet, and global positioning – not even a lifetime ago these things were mere science fiction. Today, they are commonplace,” Tyler said. “Maybe the next generation of social entertainment networks will involve downloading customized information or experiences from personalized computer clouds while encoding them into the brain using ultrasound. I see no reason to rule out that possibility.”

"To be honest,” he adds, “we simply don’t know yet how far we can push the envelope. That is why many refer to the brain as the last frontier – we still have a lot to learn."

Margaret Coulombe, margaret.coulombe">">
(480) 727-8934
School of Life Sciences