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Archive - Jan 14, 2017

Harvard Scientists Create Novel Multiregional Brain-on-a-Chip

Harvard University researchers have developed a multiregional brain-on-a-chip that models the connectivity between three distinct regions of the brain. The in vitro model was used to extensively characterize the differences between neurons from different regions of the brain and to mimic the system’s connectivity. The Harvard work was reported online on December 28, 2017 in The Journal of Neurophysiology. The article is titled “Neurons Derived from Different Brain Regions Are Inherently Different in Vitro: A Novel Multiregional Brain-On-A-Chip. “The brain is so much more than individual neurons,” said Ben Maoz, Ph.D., co-first author of the paper and postdoctoral fellow in the Disease Biophysics Group in the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). “It’s about the different types of cells and the connectivity between different regions of the brain. When modeling the brain, you need to be able to recapitulate that connectivity because there are many different diseases that attack those connections. “Roughly twenty-six percent of the U.S. healthcare budget is spent on neurological and psychiatric disorders,” said Kit Parker (photo), Ph.D., the Tarr Family Professor of Bioengineering and Applied Physics Building at SEAS and Core Faculty Member of the Wyss Institute for Biologically Inspired Engineering at Harvard University. “Tools to support the development of therapeutics to alleviate the suffering of these patients is not only the human thing to do, it is the best means of reducing this cost." The Harvard work was reported online on December 28, 2017 in The Journal of Neurophysiology. The article is titled “Neurons Derived from Different Brain Regions Are Inherently Different in Vitro: A Novel Multiregional Brain-On-A-Chip.

Researchers Create First Model of Genetically Induced Obesity in Fruit Flies

Why do people become obese? Poor dietary choices and overeating seem like clear causes, but what is at the root of these behaviors? Significantly overweight people may be genetically predisposed to be affected disproportionately when faced with the ready availability of calorie-laden treats. It appears, in others words, that some people’s genes place them at particular risk of gaining more weight than others in the modern food landscape. Scientists at Cold Spring Harbor Laboratory (CSHL) report in the January 10, 2017 issue of Cell Metabolism that they have created the first model of genetically induced obesity in fruit flies. The model can be used to study ways to dodge adverse health effects triggered by the perfect storm of genetic predisposition to obesity and calorie-rich, nutrient-poor diets. The Cell Metabolism article is titled “A Leptin Analog Locally Produced in the Brain Acts Via a Conserved Neural Circuit to Modulate Obesity-Linked Behaviors in Drosophila” Lead investigator Jen Beshel, Ph.D., who conducted the experiments while performing postdoctoral research in the laboratories of Yi Zhong, Ph.D. and Josh Dubnau, Ph.D., explains that a hormone in the fly, called unpaired 1, performs the same function as the hormone leptin in people: After its release from cells, it docks with receptors in the brain to tell the body to stop eating. Leptin is the famous dispatcher of what scientists call the “satiety” signal—the one that tells you you’re full. The idea of therapeutically administering leptin to obese people to overcome a genetically induced failure of leptin signaling emerged from research in mice first conducted at Rockefeller University in the 1990s. Dr. Beshel’s research breaks new ground.

Salmonella-Based Treatment Improves Survival Rate in 20% of Glioblastomas in Animal Model

Biomedical engineers at Duke University have recruited an unlikely ally in the fight against the deadliest form of brain cancer -- a strain of salmonella that usually causes food poisoning. Clinicians sorely need new treatment approaches for glioblastoma, the most aggressive form of brain cancer. The blood-brain barrier -- a protective sheath separating brain tissue from its blood vessels -- makes it difficult to attack the disease with drugs. It's also difficult to completely remove through surgery, as even tiny remnants inevitably spawn new tumors. Even with the best care currently available, median survival time is a dire 15 months, and only 10 percent of patients survive five years once diagnosed. The Duke team decided to pursue an aggressive treatment option to match its opponent, turning to the bacterium Salmonella typhimurium. With a few genetic tweaks, the engineers turned the bacterium into a cancer-seeking missile that produces self-destruct orders deep within tumors. Tests in rat models with extreme cases of the disease showed a remarkable 20 percent survival rate over 100 days -- roughly equivalent to 10 human years -- with the tumors going into complete remission. The results were presented online on December 15, 2016, in the journal Molecular Therapy - Oncolytics. The article is titled “Bacterial Carriers for Glioblastoma Therapy.” "Because glioblastoma is so aggressive and difficult to treat, any change in the median survival rate is a big deal," said Jonathan Lyon, a Ph.D. student working with Ravi Bellamkonda, Ph.D., Vinik Dean of Duke's Pratt School of Engineering, whose laboratory is currently transitioning to Duke from Georgia Tech, where much of the work was completed.