A View from Emily Singer
Biomedical News in Brief
Detecting autism, interrupting aging, and healing the newborn heart.
Detecting Autism in Infants
Analyzing the electrical activity in infants’ brains could predict early on which are at high risk of developing autism, according to a new study. Researchers from Children’s Hospital Boston found that they could predict with 80 percent accuracy which of a group of 79 9-month old infants (considered to be at high risk because they had a sibling with the disorder) would go on to develop autism. The research, published in BMC Medicine, used a combination of standard electroencephalogram (EEG), which records electrical activity in the brain, with machine-learning algorithms.
“Electrical activity produced by the brain has a lot more information than we realized,” said William Bosl, PhD, a neuroinformatics researcher in the Children’s Hospital Informatics Program, in a press release from the hospital. “Computer algorithms can pick out patterns in those squiggly lines that the eye can’t see.”
According to the release:
As the babies watched a research assistant blowing bubbles, recordings were made via a hairnet-like cap on their scalps, studded with 64 electrodes. When possible, tests were repeated at 6, 9, 12, 18 and 24 months of age.
Bosl then took the EEG brain-wave readings for each electrode and computed their modified multiscale entropy (mMSE) – a measure borrowed from chaos theory that quantifies the degree of randomness in a signal, from which characteristics of whatever is producing the signal can be inferred. In this case, patterns in the brain’s electrical activity give indirect information about how the brain is wired: the density of neurons in each part of the brain, how connections between them are organized, and the balance of short- and long-distance connections.
The investigators looked at the entropy of each EEG channel, which is believed to contain information about the density of neural connections in the brain region near that electrode.
On average, the greatest difference was seen at 9 months of age. The researchers note that at 9 months, babies undergo important changes in their brain function that are critical for the emergence of higher-level social and communication skills – skills often impaired in ASDs.
For reasons that still need to be explored, there was a gender difference: classification accuracy was greatest for girls at 6 months and remained high for boys at 12 and 18 months.
Researchers have created stem cells from patients with a rare accelerated aging disease called Hutchinson-Gilford Progeria Syndrome. Children with the disorder age eight to 10 times faster than normal and rarely live beyond age 13, often dying from health problems linked to early clogging of arteries and blood vessels. Scientists hope that studying these cells will help shed light on both this disorder and on normal aging.
In the study, published in Nature, researchers differentiated the stem cells into smooth muscle cells, which exhibited signs of vascular aging.
“The slow progression and complexity of the aging process makes it very hard to study the pathogenesis of cardiovascular and other aging-related disorders,” said Juan Carlos Izpisúa Belmonte, a professor in the Salk Institute’s Gene Expression Laboratory], in a release from the institute. “Having a human model of accelerated aging will facilitate the development of treatments and possibly a cure for Progeria and give us new insights into how we age. It may also help prevent or treat heart disease in the general aging population.”
Newborn Heart Heals Itself
Week old mice that had a portion of their hearts removed could re-grow the heart completely, according to new research in Science. The new heart looked and functioned like a normal heart, providing hope that scientists will be able to reanimate this regenerative capacity in older mammals.
“We found that the heart of newborn mammals can fix itself; it just forgets how as it gets older. The challenge now is to find a way to remind the adult heart how to fix itself again,” said Dr. Hesham Sadek, assistant professor of internal medicine at UT Southwestern and senior author of the study , in a press release from the university.
The researchers believe that uninjured beating heart cells, called cardiomyocytes, are a major source of the new cells. They stop beating long enough to divide and provide the heart with fresh cardiomyocytes.
…The next step, the researchers said, is to study this brief window when the heart is still capable of regeneration, and to find out how, and why, the heart “turns off” this remarkable ability to regenerate as it grows older.