MIT neuroscientists explain deja vu

CAMBRIDGE, Mass., June 12 (UPI) -- U.S. neuroscientists have identified a neuronal mechanism that helps people rapidly distinguish similar, yet distinct, places -- helping explain deja vu.

Researchers at the Massachusetts Institute of Technology's Picower Institute for Learning and Memory say their finding might lead to treatments for memory-related disorders, as well as for the confusion and disorientation that plague some elderly individuals.

Study co-author Professor Susumu Tonegawa said forming memories of places and contexts engages a part of the brain called the hippocampus. Tonegawa and colleagues have been exploring how each of the three hippocampal subregions -- the dentate gyrus, CA1 and CA3 -- contribute to learning and memory.

Tonegawa described his own occasional experience of finding the airport in a new city uncannily familiar. That occurs, he said, because of the similarity of modules -- gates, chairs, and ticket counters -- that comprise airports worldwide. It is only by seeking unique cues that the specific airport can be identified, he said.

"In this study, we have revealed that learning in the dentate gyrus is crucial in rapidly recognizing and amplifying the small differences that make each place unique," Tonegawa said.

The study appears in the early online edition of the journal Science.