Researchers Discover Key Factor in Early
Auditory System Development
Researchers at NIH have uncovered a molecule in an animal model that acts as a key player in establishing the organization of the auditory system.
Researchers at NIH have uncovered a molecule in an animal model that acts as a key player in establishing the organization of the auditory system. The molecule, a protein known as Bmp7, is produced during embryonic development and acts to help sensory cells find their ultimate position on the tonotopic map, which is the fundamental principle of organization in the auditory system. The tonotopic map groups sensory cells by the sound frequencies that stimulate them. The study is the first to identify one of the molecular mechanisms that determines position.
Findings from the study, led by Drs. Zoe F. Mann and Matthew W. Kelley of the Laboratory of Cochlear Development at NIDCD, were published in the May 20 issue of Nature Communications. The research was performed in collaboration with scientists from the University of Virginia School of Medicine and Imperial College in London. The American Hearing Research Foundation also provided support.
An additional study, appearing in the same edition, is led by NIDCD-supported researchers Dr. Benjamin R. Thiede and Dr. Jeffrey T. Corwin of UVa. Working in collaboration with Mann and Kelley, the researchers reveal that another signaling molecule, retinoic acid, acts in concert with Bmp7 to position cells.
“The findings could open doors to therapies that take advantage of Bmp7’s navigational talents to direct the formation of regenerated sensory cells that are tuned to respond to a specific frequency,” says NIDCD director Dr. James F. Battey Jr. “Since many forms of hearing loss are limited to specific frequencies, this approach could lead to replacement sensory cells that are tailored to individual needs.”
Study Links High Cholesterol Levels to Lower Fertility
High cholesterol levels may impair fertility in couples trying to achieve a pregnancy, according to a study by researchers at NIH, the University at Buffalo and Emory University.
Couples in which each partner had a high cholesterol level took the longest time to reach pregnancy. Moreover, couples in which the woman had a high cholesterol level and the man did not also took longer to achieve pregnancy when compared to couples in which both partners had cholesterol levels in the acceptable range.
“We’ve long known that high cholesterol levels increase the risk for heart disease,” said the study’s first author, Dr. Enrique Schisterman of NICHD, which led the study. “In addition to safeguarding their health, our results suggest that couples wishing to achieve pregnancy would improve their chances by first ensuring that their cholesterol levels are in an acceptable range.”
The study findings were published online in the Journal of Endocrinology and Metabolism.
Single Episode of Binge Drinking Linked to Gut Leakage, Immune System Effects
A single alcohol binge can cause bacteria to leak from the gut and increase levels of bacterial toxins in the blood, according to an NIH-funded study led by Dr. Gyongyi Szabo of the University of Massachusetts Medical School. Increased levels of these bacterial toxins, called endotoxins, were shown to affect the immune system, with the body producing more immune cells involved in fever, inflammation and tissue destruction. The article appears online in PLOS ONE.
Binge drinking is defined by NIAAA as a pattern of drinking alcohol that brings blood alcohol concentration to 0.08 g/dL or above. For a typical adult, this pattern corresponds to consuming 5 or more drinks for men, or 4 or more drinks for women, in about 2 hours.
“While the negative health effects of chronic drinking are well-documented, this is a key study to show that a single alcohol binge can cause damaging effects such as bacterial leakage from the gut into the bloodstream,” said NIAAA director Dr. George Koob.—compiled by Carla Garnett