In the early 1960s, reports began to surface that some children living in remote villages in East Africa were suffering mysterious episodes of “head nodding.” The condition, now named nodding syndrome, is recognized as a rare and devastating form of epilepsy. There were hints that the syndrome might be caused by a parasitic worm called Onchocerca volvulus, which is transmitted through the bites of blackflies. But no one had been able to tie the parasitic infection directly to the nodding heads.
Now, NIH researchers and their international colleagues think they’ve found the missing link. The human immune system turns out to be a central player. After analyzing blood and cerebrospinal fluid of kids with nodding syndrome, they detected a particular antibody at unusually high levels . Further studies suggest the immune system ramps up production of that antibody to fight off the parasite. The trouble is those antibodies also react against a protein in healthy brain tissue, apparently leading to progressive cognitive dysfunction, neurological deterioration, head nodding, and potentially life-threatening seizures.
The findings, published in Science Translational Medicine, have important implications for the treatment and prevention of not only nodding syndrome, but perhaps other autoimmune-related forms of epilepsy. As people in the United States and around the globe today observe the 10th anniversary of international Rare Disease Day, this work provides yet another example of how rare disease research can shed light on more common diseases and fundamental aspects of human biology.
Tags: Africa, antibody, autoimmune disease, autoimmunity, childhood infectious diseases, cognitive dysfunction, epilepsy, global health, immunity, infectious disease, ivermectin, leiomodin-1, neglected tropical diseases, neurons, Nodding Syndrome, Onchocerca volvulus, Onchocerciasis, parasite, parasitic worm, rare disease, Rare Disease Day, River Blindness, seizures, South Sudan, Tanzania, Uganda, worm
What might appear to be a view inside an unusual kaleidoscope is actually a laboratory plate full of ravenous roundworms (Caenorhabditis elegans) as seen through a microscope. Tens of thousands of worms (black), each about 1 millimeter in length at adulthood, are grazing on a field of bacteria beneath them. The yellow is a jelly-like growth medium called agar that feeds the bacteria, and the orange along the borders was added to enhance the sunburst effect.
The photo was snapped and stylized by NIH training grantee Adam Brown, a fourth-year Ph.D. student in the lab of David Biron at the University of Chicago. Brown uses C. elegans to study the neurotransmitter serotonin, a popular drug target in people receiving treatment for depression and other psychiatric disorders. This tiny, soil-dwelling worm is a go-to model organism for neuroscientists because of its relative simplicity, short life spans, genetic malleability, and complete cell-fate map. By manipulating the different components of the serotonin-signaling system in C. elegans, Brown and his colleagues hope to better understand the most basic circuitry in the central nervous system that underlies decision making, in this case choosing to feed or forage.
If you follow my blog, you know that I like to feature spectacular images that scientists have created during the course of their research. These images are rarely viewed outside the lab, but some are so worthy of artistic merit and brimming with educational value that they deserve a wider audience. That’s one reason why the Federation of American Societies for Experimental Biology (FASEB) launched its BioArt contest. Of the 12 winners in 2013, I’m proud to report that 11 received support from NIH. In fact, I’m so proud that I plan to showcase their work in an occasional series entitled “Snapshots of Life.” Continue reading to see the first installment—enjoy! (more…)
Posted In: Science
Tags: art, bilharzia, Federation of American Societies for Experimental Biology, flatworm, global health, immune, National Institute of Allergy and Infectious Diseases, National Institutes of Health, parasite, research, Schistosomiasis, snail, snail fever, stem cells, worm