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March 9, 2018
Digest
Epilepsy Study Links Mossy Brain Cells to Seizures and Memory Loss

A small group of cells in the brain can have a big effect on seizures and memory in a mouse model of epilepsy. According to a new study in Science, loss of mossy cells may contribute to convulsive seizures in temporal lobe epilepsy (TLE) as well as memory problems often experienced by people with the disease. The study was funded by NINDS.

“The role of mossy cells in epilepsy has been debated for decades,” said Dr. Vicky Whittemore of NINDS. “This study reveals how critical these cells are in the disease, and the findings suggest that preventing loss of mossy cells or finding ways to activate them may be potential therapeutic targets.”

New findings in a study of mice suggest that a loss of mossy cells may contribute to seizures and memory problems in a form of epilepsy.
New findings in a study of mice suggest that a loss of mossy cells may contribute to seizures and memory problems in a form of epilepsy.

IMAGE: IVAN SOLTESZ, STANFORD UNIVERSITY

Mossy cells, named for the dense moss-like protrusions that cover their surface, are located in the hippocampus, a brain area that is known to play key roles in memory. Loss of mossy cells is associated with TLE, but it is unknown what role that plays in the disease. Using state-of-the-art tools, Dr. Ivan Soltesz and his team at Stanford University were able to turn mossy cells on and off to track their effects in a mouse model of epilepsy.

“This study would not have been possible without the rapid advancement of technology, thanks in part to the BRAIN Initiative, which has encour­aged scientists to develop innovative instruments and new ways to look at the brain,” said Soltesz. “It’s remarkable that we can manipulate specific brain cells in the hippocampus of a mouse. Using 21st century tools brings us closer than ever to unlocking the mysteries behind this debilitating disease.”

In TLE, many seizures, known as focal seizures, originate in one part of the brain and are evident on electroencephalography scans that show the brain’s electrical activity. These seizures can result in symptoms such as twitching or a strange taste or smell, and many people with TLE might not be aware that these symptoms are seizures. Sometimes, focal seizures can spread throughout the entire brain becoming generalized, resulting in involuntary muscle spasms, or convulsions, that affect the limbs and other parts of the body as well as loss of consciousness.

Researchers Identify Risk Factors for Sleep Apnea During Pregnancy

Snoring, older age and obesity may increase a pregnant woman’s risk for sleep apnea—or interrupted breathing during sleep—according to researchers funded by NICHD and NHLBI. The study appears in the American Journal of Obstetrics and Gynecology.

A fresh look at the brain and breathing: NIH study in rats shows that star-shaped brain cells called astrocytes (red) may play an active role in breathing.
Snoring, older age and obesity may increase a pregnant woman’s risk for sleep apnea, according to research funded by NIH.

IMAGE: PERBOGE/THINKSTOCK

“Our study found an easy, inexpensive way to screen large numbers of women at higher risk of sleep apnea during pregnancy,” said study co-author Dr. Uma Reddy of NICHD’s Pregnancy and Perinatology Branch. “Right now, this means we’ll be able to rapidly identify women who may benefit from further testing. Depending on what we learn from future studies, our findings could also lead to improvements in pregnancy outcomes.”

In an earlier study of first-time pregnancies, the researchers found that sleep apnea increases a woman’s risk for hypertensive disorders and ges­tational diabetes. Currently, there are no medical guidelines or treatment recommendations for sleep apnea during pregnancy. NIH currently supports a study of potential treatments for pregnancy-related sleep apnea and is planning a larger one to be conducted by the NICHD-funded Maternal-Fetal Medicine Units Network.

In the current study, participants responded to questionnaires about their sleep habits, snoring and daytime sleepiness in early pregnancy (6 to 15 weeks) and mid-pregnancy (22 to 29 weeks). The women also under­went sleep apnea testing using an at-home monitoring device.

Researchers found that 3.6 percent of 3,264 women in early pregnancy and 8.3 percent of 2,512 women in mid-pregnancy had sleep apnea. Risk factors for having the condition included frequent snoring (3 or more nights per week), older maternal age and being overweight or obese as deter­mined by body mass index.

Study To Assess Biomarker as Indicator of Whether LRTIs Improve with Antibacterial Treatment

A new clinical trial sponsored by NIAID aims to determine whether low blood levels of the protein procalcitonin can reliably indicate whether a per­son’s lower respiratory tract infection will improve with antibiotic treatment.

Lower respiratory tract infections (LRTIs) can cause a variety of symptoms, including persistent coughing, wheezing, chest pain, fever and rapid or difficult breathing. Health care providers often prescribe a course of antibiotics as standard treatment without knowing for certain whether an infection is bacterial or viral. Taking antibiotics for viral infections is not only ineffective but can also introduce potential side effects and promote antimicrobial resistance.

Procalcitonin (PCT) is normally produced by the healthy human body in minute quantities and serves as a precursor to calcitonin, a hormone that helps regulate calcium levels. Currently, medical professionals are able to test patients’ blood for high PCT levels, which are an indicator of bacterial sepsis, a life-threatening complication of infection that triggers inflamma­tion throughout the body. The researchers leading the new clinical trial theorize that low PCT levels in patients with LRTIs may indicate that the infection is viral, not bacterial.

“Health care providers and patients benefit from precise diagnostic tests to guide treatment decisions,” said NIAID director Dr. Anthony Fauci. “An effective biomarker for confirming that a lower respiratory tract infection is viral and thus not treatable with antibiotics would be a significant devel­opment in our collective efforts to reduce inappropriate use of antibiotics and combat antimicrobial resistance.”

The study is being led by principal investigator Dr. Ephraim Tsalik of Duke University and the Durham VA Health Care System in Durham, N.C.

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