Recent research from the lab of Valentin Dragoi, PhD has been published in the Proceedings of the National Academy of Sciences.
Researchers injected a viral construct into the visual cortex to render neurons sensitive to blue light and hence increase their responses when an optical fiber emitted light. They subsequently monitored neural activity while animals performed a task or were sleeping for 20-30 minutes.
The study found that when animals are awake, but passive, or even when they performed a task, optogenetically-evoked electrical signals were strong, but remained local to the stimulated neural population. However, when animals were asleep, electrical signals spread out widely across the cortical circuit that they monitored. Because of this, Dragoi’s group discovered that during sleep, the coupling between neurons is strong, while they are only weakly coupled during the awake state.
First author for the paper, “Brain state limits propagation of neural signals in laminar cortical circuits,” is Natasha Kharas, MD, PhD, McGovern Medical School alumna and former student in the Dragoi lab and neurosurgery resident at Cornell Medical College. Co-authors include Ariana Andrei, PhD, and Sam Debes, PhD, postdoctoral research fellows in the Dragoi Lab.
Read more in the weekly SCOOP.