Busting a Belief About How Memories Are Made
By LIDA TUNESI
Scientists used to think that every mental task, from processing an image to forming a memory, could be attributed to a specific part of the brain. But modern neuroscience suggests that multiple brain areas work together to do a job. Usually, one area has the role of conducting the others.
For brain surgeons and their patients, knowing which brain area orchestrates a given task is crucial. Tampering with this essential area in surgery can disturb the entire network, meaning a patient could lose an ability, such as speech. So the question is: Which area, for a given task, is influencing the others?
In a recent study published in Nature Communications, Gino Del Ferraro, a research associate at City College of New York, and colleagues asked which of three brain areas — the hippocampus, the prefrontal cortex, or the nucleus accumbens — is the most important for memory formation in rats. Their results contradict popular thought on the matter.
“For decades, people believed that hubs, the most connected parts of the brain, were the most important,” Del Ferraro said. Because the hippocampus is considered a hub, most scientific thought would point to it as the leader in this task.
Del Ferraro and the research team, including postdoctoral students Byungjoon Min and Flaviano Morone as well as Professor Lucas Parra (City College of New York and The Graduate Center at CUNY) and Professor Hernan Makse (City College of New York) used computational methods to predict which area leads the other two. The group’s colleagues in Spain tested these predictions in live rats. The predictions and tests agreed: Without the nucleus accumbens, activity in the other two areas dropped.
“The nucleus accumbens is less connected to other areas than the hippocampus,” Del Ferraro said, “but it seems to be a bridge between the prefrontal cortex and the hippocampus. It’s one of few areas that allows flow between the other two areas.” The finding, he says, underscores the importance of bridges in brain networks.
The research team is now using these computational methods in a collaboration with Memorial Sloan Kettering Cancer Center to create software that predicts the effect of brain tumor surgery on language abilities, before the surgery even begins.
Gino Del Ferraro (Research Associate, The Levich Institute, CCNY) | Profile 1
Colleges and Schools
City College of New York
“Rare in-vivo study by CCNY-led team shows weak brain nodes have strong influence on memory network” (CCNY News)