Snapshots of Life: Neurons in a New Light

Mouse Midbrain

Credit: Michael Shribak, Marine Biological Laboratory, Woods Hole, MA

Birds do it, bees do it, and even educated fleas do it. No, not fall in love, as the late Ella Fitzgerald so famously sang. Birds and insects can see polarized light—that is, light waves transmitted in a single directional plane—in ways that provides them with a far more colorful and detailed view of the world than is possible with the human eye.

Still, thanks to innovations in microscope technology, scientists have been able to tap into the power of polarized light vision to explore the inner workings of many complex biological systems, including the brain. In this image, researchers used a recently developed polarized light microscope to trace the spatial orientation of neurons in a thin section of the mouse midbrain. Neurons that stretch horizontally appear green, while those oriented at a 45-degree angle are pinkish-red and those at 225 degrees are purplish-blue. What’s amazing is that these colors don’t involve staining or tagging the cells with fluorescent markers: the colors are generated strictly from the light interacting with the physical orientation of each neuron.

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Aging Research: Plasma Protein Revitalizes the Brain

Elixir of youth?For centuries, people have yearned for an elixir capable of restoring youth to their aging bodies and minds. It sounds like pure fantasy, but, in recent years, researchers have shown that the blood of young mice can exert a regenerative effect when transfused into older animals. Now, one of the NIH-funded teams that brought us those exciting findings has taken an early step toward extending them to humans.

In their latest work published in Nature, the researchers showed that blood plasma collected from the umbilical cords of newborn infants possesses some impressive rejuvenating effects [1]. When the human plasma was infused into the bloodstream of old mice, it produced marked improvements in learning and memory. Additional experiments traced many of those cognitive benefits to a specific protein called TIMP2—an unexpected discovery that could pave the way for the development of brain-boosting drugs to slow the effects of aging.

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Creative Minds: Preparing for Future Pandemics

Jonathan Abraham

Jonathan Abraham / Credit: ChieYu Lin

Growing up in Queens, NY, Jonathan Abraham developed a love for books and an interest in infectious diseases. One day Abraham got his hands on a copy of Laurie Garrett’s The Coming Plague, a 1990s bestseller warning of future global pandemics, and he sensed his life’s calling. He would help people around the world survive deadly viral outbreaks, particularly from Ebola, Marburg, and other really bad bugs that cause deadly hemorrhagic fevers.

Abraham, now a physician-scientist at Brigham and Women’s Hospital, Boston, continues to chase that dream. With support from an NIH Director’s 2016 Early Independence Award, Abraham has set out to help design the next generation of treatments to enable more people to survive future outbreaks of viral hemorrhagic fever. His research strategy: find antibodies in the blood of known survivors that helped them overcome their infections. With further study, he hopes to develop purified forms of the antibodies as potentially life-saving treatments for people whose own immune systems may not make them in time. This therapeutic strategy is called passive immunity.

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Missing Genes Point to Possible Drug Targets

Human knockout projectEvery person’s genetic blueprint, or genome, is unique because of variations that occasionally occur in our DNA sequences. Most of those are passed on to us from our parents. But not all variations are inherited—each of us carries 60 to 100 “new mutations” that happened for the first time in us. Some of those variations can knock out the function of a gene in ways that lead to disease or other serious health problems, particularly in people unlucky enough to have two malfunctioning copies of the same gene. Recently, scientists have begun to identify rare individuals who have loss-of-function variations that actually seem to improve their health—extraordinary discoveries that may help us understand how genes work as well as yield promising new drug targets that may benefit everyone.

In a study published in the journal Nature, a team partially funded by NIH sequenced all 18,000 protein-coding genes in more than 10,500 adults living in Pakistan [1]. After finding that more than 17 percent of the participants had at least one gene completely “knocked out,” researchers could set about analyzing what consequences—good, bad, or neutral—those loss-of-function variations had on their health and well-being.

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Snapshots of Life: Healing Spinal Cord Injuries

Nerve cell on a nanofiber gel

Caption: Mark McClendon, Zaida Alvarez Pinto, Samuel I. Stupp, Northwestern University, Evanston, IL

When someone suffers a fully severed spinal cord, it’s considered highly unlikely the injury will heal on its own. That’s because the spinal cord’s neural tissue is notorious for its inability to bridge large gaps and reconnect in ways that restore vital functions. But the image above is a hopeful sight that one day that could change.

Here, a mouse neural stem cell  (blue and green) sits in a lab dish, atop a special gel containing a mat of synthetic nanofibers (purple). The cell is growing and sending out spindly appendages, called axons (green), in an attempt to re-establish connections with other nearby nerve cells.

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