Feature | February 13, 2015

MR-Guided Focused Ultrasound Reverses Alzheimer’s Symptoms in Mice

Microbubbles open blood-brain barrier for more effective delivery of drugs to brain

MR guided focused ultrasound, Alzheimer's, mice, contrast media

The image on the left shows the plaque abnormalities on untreated transgenic mice and the image on the right shows the brain of a transgenic mouse that has been treated with MR imaging-guided focused ultrasound. Image courtesy of Kullervo Hynynen, Sunnybrook Research Institute.

February 13, 2015 — For the first time, researchers have reversed some of the symptoms of Alzheimer’s disease in mice using magnetic resonance (MR) imaging-guided focused ultrasound.

MR imaging-guided focused ultrasound has been shown to temporarily open the blood-brain barrier (BBB), which allows for more effective delivery of drugs to the brain. In order to accomplish this, researchers use a microbubble contrast agent. The microbubbles vibrate when they pass through the ultrasound beam, temporarily creating an opening in the BBB for the drugs to pass through. In addition, this combination of ultrasound and microbubbles has been shown to increase the number of new neurons and the dendrite length.

In this study, Kullervo Hynynen, Ph.D., a medical physicist at Sunnybrook Research Institute in Toronto, and his collaborators studied the effects of using MR imaging-guided focused ultrasound on the hippocampus of transgenic (TgCRND8) mice. Mice with this genetic variant have increased plaque on their hippocampus, the part of the brain that helps convert information from short-term to long-term memory; they also display symptoms similar to Alzheimer’s such as memory impairment and learning reversal. Thus, transgenic mice are used as an animal model for Alzheimer’s disease.

The researchers used MR imaging-guided focused ultrasound with microbubbles to open the BBB and treat the hippocampus of the mice. The researchers treated each side separately to be as accurate as possible in their focus of the ultrasound beam. They found the treatment led to improvements in cognition and spatial learning in the transgenic mice, potentially caused by reduced plaque and increased neuronal plasticity due to the focused ultrasound treatment. They found no tissue damage or negative behavioral changes in the mice due to the treatments in either the transgenic mice or the control (nontransgenic) mice. Both groups of mice benefited from increased neuronal plasticity, which confirms the previous research on the effects of MR imaging-guided focused ultrasound on plasticity in healthy mice.

An estimated 5.2 million Americans suffer from Alzheimer’s. It is the sixth leading cause of death in the United States and there is currently no treatment for the disease. “The results are an exciting step in the search for Alzheimer’s treatments,” said Steven Krosnick, M.D., program director for image-guided interventions at the National Institute of Biomedical Imaging and Bioengineering at NIH, “but there is more to be done. There are limitations on the memory tests that can be done on mice, and human cognition is significantly more complex. Hopefully these results will open doors to more research on how MR imaging-guided focused ultrasound could benefit cognition and perhaps be magnified by using other therapeutics in conjunction with this method.”

For more information: www.nibib.nih.gov

Related Content

Doctor-Patient Discussions Neglect Potential Harms of Lung Cancer Screening
News | Lung Cancer | August 15, 2018
August 15, 2018 — Although national guidelines advise doctors to discuss the benefits and harms of...
Fujifilm SonoSite Unveils Full Suite of iViz Point-of-Care Transducers

The L25v ultrasound transducer for the Fujifilm Sonosite iViz is available for superficial applications such as ophthalmic, arterial, venous, lung and nerve. Image courtesy of Fujifilm Sonosite.

Technology | Ultrasound Imaging | August 15, 2018
Fujifilm SonoSite Inc. announced the launch of two new transducers for the SonoSite iViz point-of-care ultrasound, now...
Guerbet Partners With Imalogix on Dose Optimization With Artificial Intelligence
News | Radiation Dose Management | August 14, 2018
August 14, 2018 — Guerbet LLC USA announced a commercial partnership with Imalogix, a provider of...
Videos | Magnetic Resonance Imaging (MRI) | August 13, 2018
Haojie Wang, M.D., director of advanced cardiovascular MRI and a member of the heart valve clinic at Baylor Scott Whi
ACR LI-RADS Steering Committee Releases New Version of CT/MRI LI-RADS
News | Clinical Decision Support | August 13, 2018
August 13, 2018 — The American College of Radiology Liver Imaging Reporting and Data System (LI-RADS) steering commit
Exact Imaging Becomes UroGPO Imaging Partner
News | Ultrasound Imaging | August 10, 2018
Exact Imaging announced that it has become a UroGPO Imaging Partner, joining the North American urology-specific group...
Indiana Hospital Installs First Vantage Titan/Zen Edition 1.5T MRI in U.S.
News | Magnetic Resonance Imaging (MRI) | August 10, 2018
Patients in Pulaski County, Ind., now have access to quiet, comfortable magnetic resonance (MR) exams thanks to the...
3T MRI Installed at The London Clinic Through Hospital Roof

Image courtesy of The London Clinic

News | Magnetic Resonance Imaging (MRI) | August 08, 2018
Patients at The London Clinic, a private hospital and charity, will be the first in the United Kingdom to access the...
Aidoc Receives FDA Clearance for AI Detection of Acute Intracranial Hemorrhage
Technology | Clinical Decision Support | August 08, 2018
Aidoc announced that it was granted U.S. Food and Drug Administration (FDA) clearance for the first product of its...
Cardiac Imaging Reveals Roots of Preeclampsia Damage in Pregnant Women
News | Women's Health | August 07, 2018
Johns Hopkins researchers say a heart imaging study of scores of pregnant women with the most severe and dangerous form...
Overlay Init