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An abnormally overactive neural activity might lie at the root of the schizophrenia, Massachusetts Institute of Technology researchers suggest. Patients suffering from schizophrenia normally suffer from a breakdown of organized thought which is often accompanied by hallucinations.

MIT neuroscientists found that mice lacking the brain protein calcineurin have hyperactive brain-wave oscillations in the hippocampus when they rest. In the mean time they completely forget the route they have just run which is not normal.

Previously mutations in the gene for calcineurin has been found in patients suffering from schizophrenia.

As a part of the research, Susumu Tonegawa, the Picower Professor of Biology and Neuroscience along with other colleagues recorded the electrical activity of individual neurons in the hippocampus as mice ran along a track.

Researchers found that mice lacking calcineurin had normal brain activity as they ran the course. But once mice paused, their ripple events were strongly frequent.

“We think that in this mouse model, we may have some kind of indication that there’s a disorganized thinking process going on,” says Junghyup Suh, a research scientist at the Picower Institute and one of the paper’s lead authors in a press release. “During ripple events in normal mice we know there is a sequential replay event. This mutant mouse doesn’t seem to have that kind of replay of a previous experience.”

The other lead author of the research paper is David Foster who is a former MIT postdoc. Other authors include Heydar Davoudi and Matthew Wilson, the Sherman Fairchild Professor of Neuroscience at MIT who are the members of the Picower Institute.

“It looks like this abnormally high LTP has an impact on activity of these cells specifically during resting periods, or post exploration periods. That’s a very interesting specificity,” Tonegawa added. “We don’t know why it’s so specific.”

However further studies might reveal more about the default mode network in schizophrenia, Tonegawa says. The sudy is published in the Oct. 16 issue of the juornal Neuron.