Toward better understanding BOLD

YOUTUBE, ZEUS CHIRIPANeuroscientists have used blood oxygen level–dependent functional magnetic resonance imaging (BOLD fMRI) for years, but aren’t exactly sure what the brain scans pick up. Is it neuronal firing tied to blood flow? Something else?

“This means that if BOLD shows you a large blob of activity, that doesn’t necessarily mean that all the neurons in that region are spiking,” David Attwell of University College London who helped organized a recent meeting on BOLD told The Scientist. “So what we really need to know is how neurons are influencing blood flow.”

“There’s this idea that if we can link BOLD to neuronal activity—that would be nirvana,” said Bojana Stefanovic of Toronto’s Sunnybrook Research Institute. “Clinicians, however, are looking for measures with a clear link to symptoms. And, fortunately, there is no shortage of disease effects BOLD can sense.”

Breast milk sugars fuel gut...

WIKIMEDIA, CCOSTELLA team led by investigators at the Washington University School of Medicine in St. Louis has identified oligosaccharides from mammalian breast milk that seem to support a web of gut microbes that in turn bolster infant growth. The group’s results were published in Cell this week (February 18).

“We were interested in milk oligosaccharides because they are largely indigestible by us but are broken down by the microorganisms of our gut microbiota,” said study coauthor Mark Charbonneau of Washington University.

“The ultimate goal is an intervention study to show that [oligosaccharide supplementation] works in humans,” said Lars Bode of the University of California, San Diego, who was not involved in the work.

Astrocytes in flux

TODD FARMER, MCGILL UNIVERSITY HEALTH CENTREThrough sonic hedgehog signaling, neurons can manipulate the identities of nearby astrocytes, scientists from McGill University in Montreal and their colleagues reported in Science this week (February 18).

“The key message is that astrocytes’ molecular fate is not hardwired,” said Cagla Eroglu of Duke University in Durham, North Carolina, who was not involved in the research.

“What’s very exciting about the paper is this notion that a cell’s fate might be determined—after it has already established its morphology and location in the brain—based on interactions with its neighbors,” noted Ed Ruthazer of McGill who also was not involved in the study.

Other news in life science:

Zika Update (February 19)
Virus found in amniotic fluid; scientists consider links to mental illness, global warming, dengue, and Guillain-Barré syndrome

Zika Update (February 16)
Uptick in Guillain-Barré syndrome; Zika data-sharing snags; Brazilian state discontinues larvicide

New CRISPR Patent Issued
Caribou Biosciences earns IP protection related to the gene-editing technology.

Gamers Publish Paper
Players of the online RNA-building game eteRNA publish a set of rules linking an RNA’s shape with the difficulty of synthesizing it.

NIH Grant Reviews Don’t Predict Success
Peer reviewers’ assessments of funding proposals to the National Institutes of Health don’t correlate well with later publication citations, a study shows.

Detecting Lyme Early
Two new methods could help researchers to diagnose Lyme disease earlier than with existing tests.

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