Susumu Tonegawa’s presence announces itself as soon as you walk through the door of the Massachusetts Institute of Technology’s Picower Institute for Learning and Memory.
The parallel circuits may also help us integrate present information with older memories just as speedily: Memories of a new conversation with your friend Shannon can be added seamlessly to your existing memories of Shannon.
In addition to revealing that different mechanisms control memory formation and recall, Tonegawa, Roy and their colleague Takashi Kitamura have shown that memory formation itself is unexpectedly complex.
Their work concerned the brain changes involved in the transformation of short-term memories to long-term memories. Tonegawa’s team recently reported in Science that new memories form at both locations at the same time. The road to that discovery started back in 2012, when Tonegawa’s lab came up with a way to highlight brain cells known as engram cells, which hold a unique memory.
“You can demonstrate those are the cells really holding this memory,” Tonegawa said, “Because if you reactivate only those neurons with laser light, the animal behaves as if recalling that memory.”