Brent Kearney

Researchers at the Massachusetts Institute of Technology (MIT) have come up with an impressive new technique for studying live brain activity. The technique allows them to view cellular-resolution live imaging, non-invasively, from a genetically engineered animal’s brain as it moves about its environment. They came up with the technique as a means to study the role of a particular neural protein, “Arc”, however it can be used for a wide range of studies on the brain.

This advance, coupled with other brain disease models, could “offer unparalleled advantages in understanding pathological processes in real time, leading to potential new drugs and treatments for a host of neurological diseases and mental disorders,” said Nobel laureate Susumu Tonegawa, a co-author of the study.

The scientists’ new imaging system revealed that the Arc gene helps strengthen synapses in the hippocampus during the formation of visual memories, and also inhibits the activity of neurons with “low orientation selectivity” for the visual experience being remembered. The strengthening of neural synapses in this area has the effect of sharpening orientation selectivity as particular visual stimuli are experienced. They witnessed a hitherto unknown molecular filtering mechanism in action, the process by which visual memories are created.

The imaging system made use of a genetically engineered mouse and two-photon microscopy. The mouse was engineered so that part of the protein under investigation, Arc, was replaced by a phosphorescent jellyfish gene, which then left a fluorescent trace when neural activities that normally activate the Arc gene occurred. “This allowed the researchers to image neuronal activation patterns induced by visual experience, thus uncovering the Arc protein’s role in orchestrating neurons’ reactions to natural sensory stimuli.”

This will definitely not be the last that we hear of this technology. Many mysteries still remain in brain science, and this new imaging technique promises to unlock many of them. Here is the official MIT press release.