Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Traffic jam in brain causes schizophrenia symptoms

13.08.2009
Scientists create first mouse to develop disease as teenager, just like humans

Schizophrenia waits silently until a seemingly normal child becomes a teenager or young adult. Then it swoops down and derails a young life.

Scientists have not understood what causes the severe mental disorder, which affects up to 1 percent of the population and results in hallucinations, memory loss and social withdrawal.

But new research from the Northwestern University Feinberg School of Medicine has revealed how schizophrenia works in the brain and provided a fresh opportunity for treatment. In a new, genetically engineered mouse model, scientists have discovered the disease symptoms are triggered by a low level of a brain protein necessary for neurons to talk to one another.

A Traffic Jam in Brain

In human and mouse brains, kalirin is the brain protein needed to build the dense network of highways, called dendritic spines, which allow information to flow from one neuron to another. Northwestern scientists have found that without adequate kalirin, the frontal cortex of the brain of a person with schizophrenia only has a few narrow roads. The information from neurons gets jammed up like rush hour traffic on an interstate highway squeezed to a single lane.

"Without enough pathways, the information takes much longer to travel between neurons and much of it will never arrive," said Peter Penzes, assistant professor of physiology at the Feinberg School. He is senior author of a paper reporting the findings published in a recent issue of the Proceedings of the National Academy of Science. Michael Cahill, a Feinberg doctoral student in neuroscience, is the lead author.

First Mouse Model to Develop Disease as a Teenager

Penzes discovered the kalirin effect after he created the mouse model, which was the first to have a low level of kalirin and the first to develop symptoms of schizophrenia as an adolescent (two months old in mouse time). This mimics the delayed onset of the disease in humans. In normal development, the brain ramps up the production of kalirin as it begins to mature in adolescence.

New Direction for Treatment

"This discovery opens a new direction for treating the devastating cognitive symptoms of schizophrenia," Penzes said. "There is currently no treatment for that. It suggests that if you can stimulate and amplify the activity of the protein kalirin that remains in the brain, perhaps we can help the symptoms."

Currently the only drug treatment for schizophrenia is an antipsychotic. "The drugs address the hallucinations and calm down the patient, but they don't improve their working memory (the ability of the brain to temporarily store and manage information required for complex mental tasks such as learning and reasoning) or their ability to think or their social behavior," Penzes said. "So you end up with patients who still can't integrate into society. Many attempt suicide."

Similarities Between Human and Mouse Brains

A few years ago in postmortem examinations of schizophrenic human brains, other scientists had found fewer connections between the brain cells in the frontal cortex and lower levels of kalirin. But the scientists couldn't show whether one condition led to the other.

With the new mouse model, Penzes was able to demonstrate that the low level of kalirin resulted in fewer dendritic spines in the frontal cortex of the brain, the part of the brain responsible for problem solving, planning and reasoning. Other areas of the brain had a normal number of the dendritic spines. Human brains and mouse brains share many similarities in the way they function, Penzes said.

The new schizophrenic mouse model also exhibits more schizophrenic symptoms than other models, making these mice especially good for drug testing and development, Penzes said. The mice with low amounts of kalirin had a poor working memory, were antisocial and hyperactive.

Penzes said future studies would aim at enhancing the function of kalirin in the brain in an effort to correct the cognitive symptoms of schizophrenia.

Marla Paul | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Health and Medicine:

nachricht Why might reading make myopic?
18.07.2018 | Universitätsklinikum Tübingen

nachricht Unique brain 'fingerprint' can predict drug effectiveness
11.07.2018 | McGill University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>