Warren symposium follows legacy of geneticist giant

If we want to understand how the brain creates memories, and how genetic disorders distort the brain’s machinery, then the fragile X gene is an ideal place to start. That’s why the Stephen T. Warren Memorial Symposium, taking place November 28-29 at Emory, will be a significant event for those interested in neuroscience and genetics. Stephen T. Warren, 1953-2021 Warren, the founding chair of Emory’s Department of Human Genetics, led an international team that discovered Read more

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Tracing the start of COVID-19 in GA

At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia. Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more

blood oxygen

Dynamic functional connectivity

How can neuroscientists tell that distant parts of the brain are talking to each other?

They can look for a physical connection, like neurons that carry signals between the two. They could probe the brain with electricity. However, to keep the brain intact and examine cheap oakley function in a living person or animal, a less invasive approach may be in order.

Looking for functional connectivity has grown in popularity in recent years. This is a way of analyzing fMRI (functional magnetic resonance imaging) scans, which measure activity in the brain by looking at changes in blood oxygen. If two regions of the brain “light up” at the same time, and do so in a consistent enough pattern, that indicates that those two regions are connected.*

Functional connectivity networks

Shella Keilholz and her colleagues have been looking at functional connectivity data very closely, and how the apparent connections fluctuate over short time periods. This newer form of analysis is called “dynamic” or “time-varying” functional connectivity. Functional connectivity analyses can be performed while the person or animal in the scanner is at rest, not doing anything complicated.

“Even if you’re lying in the scanner daydreaming, your mind is jumping around,” she says. “But the way neuroscientists usually average fMRI data over several minutes means losing lots of information.”

Keilholz is part of the Wallace H Coulter Department of Biomedical Engineering at Georgia Tech and Emory. She participated in a workshop at the most recent Human Brain Mapping meeting in Seattle devoted to the topic. She says neuroscientists have already started using dynamic functional connectivity to detect differences in the brain’s network properties in schizophrenia. However, some of that information may be noise. Skeptical tests have shown that head motion or breathing can push scientists into inferring connections that aren’t really there. For dynamic analysis especially, preprocessing can lead to apparent correlations between two randomly matched signals.

“I got into this field as a skeptic,” she says. “Several years ago, I didn’t believe functional connectivity really reflects coordinated brain activity.”

Now Keilholz and her colleagues have shown for the first time that dynamic functional connectivity data is “grounded”, because it is linked with changes in electrical signals within the brain. The results were published in July in the journal NeuroImage. The first author is graduate student Garth Thompson. Read more

Posted on by Quinn Eastman in Neuro Leave a comment