July 31, 2013. People with schizophrenia may hold bizarre beliefs—delusions—that strike the rest of us as plainly untrue: For example, they may be convinced that they are Jesus reborn, or they may fear that extraterrestrials have implanted devices in their brains. In the hope of safely and effectively dislodging such debilitating notions, researchers have been trying to understand how they take root in the first place. One idea is that delusions result when the brain makes mistakes while creating memories.
Researchers have found a way for mistaken memories to take root by creating a false memory in mice, according to a study published July 25 in Science. To do this, Susumu Tonegawa of the Massachusetts Institute of Technology, Cambridge, and colleagues identified a network of brain cells that represented the memory for a place—a cage the mice had visited. The researchers then placed the mice in a different cage, one where they received a mild foot shock . While this happened, Tonegawa's researchers activated the network of cells that represented the memory for the first, harmless cage. Afterwards, they asked whether the first cage would scare the mice. It did: Mice sat frozen in fear more than they usually would in a familiar place, or even in a new environment. Thus, a false memory of shock in the first cage had been created.
Although the findings deal with a specific, simple form of learning, Carol Tamminga, a schizophrenia researcher at the University of Texas Southwestern Medical Center at Dallas, who was not involved in the study, told SRF that they might have implications for a person with a firmly held complex delusion. “For me, the promise of the study is that we'll soon have real physiological mechanisms that will help us explain what we now think of as bizarre mental events, but which are just mistakes of brain function,” she said. (For more details, see the related news story.)—Michele Solis.