A probe that binds to synaptic proteins allows scientists to see how the brain changes after you learn something. Photo: Patrick Hoesly
Using a protein found in glowing jellyfish and some fancy engineering, scientists can now watch memories as they form in the brains of mice.
That alone is cool, but here’s the real sci-fi stuff: Within a couple years, researchers think they’ll be able to selectively eliminate memories (at least in mice), much like they do in the John Woo-Ben Affleck classic Paycheck or Eternal Sunshine of the Spotless Mind.
Joking aside, here’s how it works: Your brain is made up of 100 billion neurons that are connected by synapses, which pass electrical communications between each other. When you learn something new, the brain creates new connections between the synapses.
“The pattern of synapses—how strong these connections are—is the physical substrate of learning and memory,” said Don Arnold, a researcher at the University of Southern California and author of the study published in Neuron. “When you learn something, it’s this pattern of connections that gets changed. If you could label these, you could get an idea of how the structure of the brain changes when an animal learns or when something is remembered.”
That’s where the jellyfish protein comes in: Arnold and his colleagues created fluorescent “probes” using that can be injected into the brain and bind to synaptic proteins. By then exposing a mouse to a new task, they are able to see how the brain’s synapses look before and after this exposure.
Arnold says the process would be useful for studying disorders such as Fragile X syndrome, which causes autism and mental retardation and is related to synaptic strength. The process might also be used to test new drugs that target brain disorders. Because the process of watching a brain as it learns is pretty invasive, there aren’t any plans to try this out in humans.
While Arnold’s initial research is certainly interesting, it’s what he and other scientists plan to do next with the research that’s really out there. The team is working on a way of eliminating memories of learned behavior entirely from mice.
“We’re in the process of adapting this technology to do exactly that,” Arnold said when I asked about the possibility of erasing memories. “There’s two parts to our current probe—there’s the fluorescent protein part, but then there’s also the part that targets the protein to an individual molecule.”
He says they can theoretically engineer probes that can cause the synaptic proteins to degrade, a project they’re currently “finishing up.” But animal tests using the technology are probably a couple years down the road, he said.
“The idea, the dream experiment, would be to have the animal learn something, then look at which synapses have changed, and then go in and delete those synapses to see if the animal has unlearned it,” he said.
What happens then is anyone’s guess. Scientists aren’t sure if once a synapse is denatured if the same synapses will grow back once an animal is re-exposed to the same behavior or memory, if they will create patterns in other parts of the brain, or if they will be completely unable to relearn the behavior. No word on whether the process will stop you from making the same mistakes with your ex.
“The answer is, who knows,” he said. “But that’s the experiment we’d envision. But we’re developing these probes and we want to use them.”