When you do a hard workout at the gym, or run a marathon, you generate lots of little tears in muscle. This is usually not a problem and may even lead to improved muscle strength—because the injury activates stem cells in the muscle (called satellite cells) that replicate and form new muscle fibers to repair and rebuild the damaged tissue. But when injuries extend beyond the normal wear and tear—a major injury or resection, for example—this amazing self-healing system isn’t enough. That’s when a self-healing, lab-grown muscle transplant would be particularly useful—but we haven’t yet been able to create this in a dish.
Anyone who’s taken part in a water balloon fight knows what happens when you fill a balloon with too much water—it bursts. Now, consider that most of our cells are essentially water balloons: a thin membrane envelope containing a mixture that’s mostly water along with some salts, proteins, lipids, carbohydrates, and nucleic acids. Given that the average adult’s body is about 60% water, what keeps our cells from overfilling and exploding?
A few years ago, Zhaozhu Qiu, a postdoctoral fellow in Ardem Patapoutian’s lab at Scripps Research Institute in La Jolla, CA, decided to dig into the molecular details of how cells are able to sense their volume and adjust their shapes accordingly. It’s long been known that, when cells are placed in low-salt solutions, water tends to flow into them, causing them to swell—sometimes to the verge of bursting. Scientists determined, about 30 years ago, that, when this occurs, channels in the cell membrane open and the cells release chloride and other molecules, such as amino acids: a process that drives out the excess water and returns cells to their normal size .
Relief of anxiety and stress is one of the most common reasons that people give for using marijuana . But the scientific evidence is rather sparse about whether there’s a biological explanation for that effect.
More than a decade ago, researchers set out to explore the link between marijuana and anxiety reduction, but the results of their experiments were inconclusive . Recently, a team led by NIH-funded researchers at Vanderbilt University Medical Center in Nashville decided to tackle the question again, this time using more sensitive tools that have just become available in recent years.
There is mounting evidence that predisposition to autism, schizophrenia, and many other devastating brain disorders may begin in the womb when genes are turned on or off at the wrong time during early brain development. But because our current maps of the developing brain are not nearly as detailed or dynamic as we would like, it has been a major challenge to identify and understand the precise roles of these genes.
So, I’m pleased to report that NIH-funded researchers at the Allen Institute for Brain Science in Seattle have produced a comprehensive 3-D map that reveals the activity of some 20,000 genes in 300 brain regions during mid-prenatal development . While this is just the first installment of what will be an atlas of gene activity covering the entire course of human brain development, this rich trove of data is already transforming the way we think about neurodevelopmental disorders.
Today, I’d like to wish a very “Happy Birthday” to a dear friend and one of my personal heroes: Jane Goodall. Given Jane’s energy and youthful attitude, it’s hard to believe that this scientist who was so instrumental in advancing our understanding of primate behavior is turning 80 today.
But, indeed, more than a half-century has passed since Jane first traveled to Africa to begin her field research in Gombe National Park on the shores of Africa’s Lake Tanganyika. Her goal? To observe wild chimpanzees in their natural environment and analyze their behavior like no researcher had done before.
At first, the chimps were shy and ran away whenever Jane approached. But, as they grew used to the young biologist’s presence, they continued on with their daily activities as she carefully watched and meticulously recorded their actions, often equipped with nothing more than a pair of binoculars, a pencil, and a notebook. Her landmark work revealed that chimp behavior resembled human behavior in ways that no one had even imagined—findings that transformed our understanding of our closest relatives in the animal kingdom. Continue reading