Altered brain activity responsible for cognitive symptoms of schizophrenia

March 20, 2013, Cell Press

Cognitive problems with memory and behavior experienced by individuals with schizophrenia are linked with changes in brain activity; however, it is difficult to test whether these changes are the underlying cause or consequence of these symptoms. By altering the brain activity in mice to mimic the decrease in activity seen in patients with schizophrenia, researchers reporting in the Cell Press journal Neuron on March 20 reveal that these changes in regional brain activity cause similar cognitive problems in otherwise normal mice. This direct demonstration of the link between changes in brain activity and the behaviors associated with schizophrenia could alter how the disease is treated.

"We artificially decreased activity of the mediodorsal thalamus region of the brain in the mouse and found that it is sufficient to lead to deficits in and other schizophrenia-like cognitive deficits," says senior author Dr. Christoph Kellendonk of Columbia University in New York City. "Our findings further suggest that decreased thalamic activity interferes with cognition by disrupting communication between the thalamus and the prefrontal cortex, an area of the brain that has already been shown to be important for working memory," he added.

The researchers made their discovery by giving mice a drug that decreased activity selectively in the mediodorsal thalamus region of the brain. They then tested the animals in various involving levers and mazes. The investigators found that even a subtle decrease in the activity of the mediodorsal thalamus led to altered connectivity between this brain region and the prefrontal cortex region and that the altered connectivity was associated with a variety of cognitive impairments experienced by patients with schizophrenia.

The findings likely apply to humans because patients with schizophrenia have decreased thalamic activity as well as altered connectivity between the thalamus and the prefrontal cortex. "Our work suggests that these two findings may be linked," explains co-senior author Dr. Joshua Gordon, also of Columbia University. "One next step would be to examine this relationship in patients. For example, one could ask whether deficits in thalamic activity and connectivity between the thalamus and are correlated with each other."

Cognitive symptoms of schizophrenia include problems with memory and behavioral flexibility, two processes that are essential for activities of daily living. These symptoms are resistant to current treatments, but this study's findings provide new information for the design of potentially more effective therapies that target the neuronal mechanisms underlying patients' cognitive problems.

Explore further: How cannabis causes 'cognitive chaos' in the brain

More information: Neuron, Parnaudeau et al.: "Inhibition of medio-dorsal thalamus disrupts thalamo-frontal connectivity and cognition." dx.doi.org/10.1016/j.neuron.2013.01.038

Related Stories

How cannabis causes 'cognitive chaos' in the brain

October 25, 2011
Cannabis use is associated with disturbances in concentration and memory. New research by neuroscientists at the University of Bristol, published in the Journal of Neuroscience, has found that brain activity becomes uncoordinated ...

Could poor sleep contribute to symptoms of schizophrenia?

November 14, 2012
Neuroscientists studying the link between poor sleep and schizophrenia have found that irregular sleep patterns and desynchronised brain activity during sleep could trigger some of the disease's symptoms. The findings, published ...

Shedding light on memory deficits in schizophrenic patients and healthy aged subjects

February 23, 2012
Working memory, which consists in the short-term retention and processing of information, depends on specific regions of the brain working correctly. This faculty tends to deteriorate in patients with schizophrenia, as it ...

Researchers gain new insight into prefrontal cortex activity

March 5, 2012
The brain has a remarkable ability to learn new cognitive tasks while maintaining previously acquired knowledge about various functions necessary for everyday life. But exactly how new information is incorporated into brain ...

Induction of mild inflammation leads to cognitive deficits related to schizophrenia

February 6, 2013
Researchers at the Institute for Comprehensive Medical Science, Fujita Health University and the National Institute for Physiological Sciences, Japan, along with colleagues from 9 other institutions, have identified an exceptional ...

Recommended for you

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.