hackingbear writes: While the general steps of forming a long-term memory are clear, the details, such as how exactly the molecular signals get shuttled to the command center, which generally has tight security, are unclear. A new study, led by neuroscientist Yi Zhong of Tsinghua University in Beijing, may finally have that answer. In the tiny minds of fruit flies, a protein called importin-7 acts to shuttle the memory-triggering signal into the nucleus with its top-level clearance to the restricted area, researchers report in the Proceedings of the National Academy of Sciences. With genetic tweaking, the researchers dialed up and down the amount of importin-7 in the flies and then put them through the memory training and test. They found that cranking up levels of the shuttle protein strengthened the long-term memories of the flies, while turning it off weakened their memory. "The current work confirms that [importin-7] is indeed critical at the behavioral level in mediating [long-term memory] consolidation," the authors concluded.