Focused ultrasound (FUS) can be used to help drugs pass from the bloodstream into the brain, but the technique’s effectiveness depends on the ultrasound pressure and the size of the drug molecules. Michael Valdez and colleagues at the University of Arizona measured how thoroughly differently sized molecules diffused into mouse brains under a range of ultrasound intensities, and found that the largest molecules could not be delivered under any safe FUS regime. The results set a limit on the types of drugs that might one day be used to treat neurological conditions like Alzheimer’s and Parkinson’s disease (Ultrasound Med. Biol. 10.1016/j.ultrasmedbio.2019.08.024).

Usually, the brain is isolated from substances circulating in the bloodstream by the blood–brain barrier (BBB), a semipermeable layer of cells that permits only certain molecules to pass. This restricts the range of drugs that can be used in the brain to small, hydrophobic molecules (such as alcohol and caffeine), other small drugs like psychotropics and some antibiotics. Extending that range would open the door to new therapeutic possibilities, says Theodore Trouard, who led the team. “The ability to temporarily and safely open the BBB to allow drugs into the brain would help address a number of neurological diseases for which there is currently no effective treatment.”

Previous research has shown that such opening can be achieved by focusing an ultrasound beam in the brain while gas microbubbles circulate in the blood. The microbubbles – perfluorocarbon-filled lipid shells about 1 µm across – are inert while they move around the body, but rapidly expand and contract in the local pressure fluctuations caused by the ultrasound field. Mechanical forces exerted by this phenomenon create temporary gaps in the layer of cells that make up the BBB, giving larger molecules a chance to breach the brain’s defences.

Authorities in China have approved a drug for the treatment of Alzheimer’s disease, the first new medicine with the potential to treat the cognitive disorder in 17 years.

The seaweed-based drug, called Oligomannate, can be used for the treatment of mild to moderate Alzheimer’s, according to a statement from China’s drug safety agency. The approval is conditional however, meaning that while it can go on sale during additional clinical trials, it will be strictly monitored and could be withdrawn should any safety issues arise.

In September, the team behind the new drug, led by Geng Meiyu at the Shanghai Institute of Materia Medica under the Chinese Academy of Sciences, said they were inspired to look into seaweed due to the relatively low incidence of Alzheimer’s among people who consume it regularly.

Oct. 29 is World Stroke Day. Sometimes called a brain attack, stroke is the second leading cause of death worldwide and the fifth leading cause of death in the U.S. Men and women are at risk of a stroke, but women are more likely to have – and die – of a stroke than men. Dr. Kara Sands, a Mayo Clinic neurologist, says stroke kills twice as many women as breast cancer. The good news is that strokes are preventable, treatable and beatable.

Watch: The Mayo Clinic Minute

Journalists: Broadcast-quality video (0:59) is in the downloads at the end of this post. Please “Courtesy: Mayo Clinic News Network. ”Read the script.

One of the most intriguing developments in the so-called golden age of neuroscience has been the growing understanding of “neuroplasticity”: the brain’s ability to constantly reshape itself and constantly learn new things by forging new connections throughout one’s lifetime — to grow proportions of gray matter and even shift brain activity to different regions of the brain.

Now a new research effort is taking the concept of neuroplasticity further — looking at diseased and injured brains that have permanently lost neurons. The effort, led by neuroscientist Magdalena Götz, explores whether “astrocytes” — non-neuronal, structural cells in the brain, can be reprogrammed to take up the tasks the neurons once performed.

“Everybody is astonished, at the moment, that it works,” says Nicola Mattugini, a neurobiologist at the Ludwig Maximilian University of Munich, Germany, when she presented her team’s results at the annual meeting of the Society for Neuroscience in San Diego, California. Their team reprogrammed the astrocytes in lab mice.