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

Reddit as window into opioid withdrawal strategies

Drug abuse researchers are using the social media site Reddit as a window into the experiences of people living with opioid addiction. Abeed Sarker in Emory's Department of Biomedical Informatics has a paper in Clinical Toxicology focusing on the phenomenon of “precipitated withdrawal,” in collaboration with emergency medicine specialists from Penn, Rutgers and Mt Sinai. Precipitated withdrawal is a more intense form of withdrawal that can occur when someone who was using opioids starts medication-assisted treatment Read more

CROI: HIV cure report and ongoing research

The big news out of CROI (Conference on Retroviruses and Opportunistic Infections) was a report of a third person being cured of HIV infection, this time using umbilical cord blood for a hematopoetic stem cell transplant. Emory’s Carlos del Rio gave a nice overview of the achievement for NPR this morning. As del Rio explains, the field of HIV cure research took off over the last decade after Timothy Brown, known as “the Berlin patient,” Read more

SCN8A

Epilepsy pick up sticks

Imagine the game of pick up sticks. It’s hard to extract one stick from the pile without moving others. The same problem exists, in a much more complex way, in the brain. Pulling on one gene or neurotransmitter often nudges a lot of others.

Andrew Escayg, PhD

That’s why a recent paper from Andrew Escayg’s lab is so interesting. He studies genes involved in epilepsy. Several years ago, he showed that mice with mutations in the SCN8A gene have absence epilepsy, while also showing resistance to induced seizures. SCN8A is one of those sticks that touches many others. The gene encodes a voltage-gated sodium channel, involved in setting the thresholds for and triggering neurons’ action potentials. Mutating the gene in mice modifies sleep and even enhances spatial memory.

Escayg’s new paper, with first author Jennifer Wong, looks at the effect of “knocking down” SCN8A in the hippocampus in a mouse model of mesial temporal lobe epilepsy. This model doesn’t involve sodium channel genes; it’s generated by injection of a toxin (kainic acid) into the brain. The finding suggests that inhibiting SCN8A may be applicable to other forms of epilepsy. Escayg notes that mesial temporal lobe epilepsy is one of the most common forms of treatment-resistant epilepsy in adults.

Knocking down SCN8A in the hippocampus 24 hours after injection could prevent the development of seizures in 90 percent of the treated mice. “It is likely that selective reduction in Scn8a expression would have directly decreased neuronal excitability,” the authors write. It did not lead to increased anxiety levels or impaired learning/memory.

Currently, no available drugs target Scn8a specifically. However, antisense approaches for neurodegenerative diseases have been gaining ground – perhaps epilepsy could fit in.

Posted on by Quinn Eastman in Neuro Leave a comment