Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mice with defective memory may hold clues to schizophrenia

18.01.2006


By deleting a single gene in a small portion of the brains of mice, researchers at UT Southwestern Medical Center found that the animals were affected in a way resembling schizophrenia in humans.



After the gene was removed, the animals, which had been trained to use external cues to look for chocolate treats buried in sand, couldn’t learn a similar task, the researchers report in a paper appearing in today’s issue of The Journal of Neuroscience.

The researchers deleted the gene, which codes for a part of a protein involved in passing signals between nerve cells needed for learning and memory. When a similar protein is blocked by drugs in humans, it leads to a psychotic state similar to schizophrenia.


"We think that both our genetic rodent model as well as a new learning and memory test we developed may provide valuable tools in the investigation of schizophrenia," said Dr. Robert Greene, professor of psychiatry and senior author of the study.

The researchers developed the training method to test the animals’ memories. Chocolate was buried in a cup containing scented sand, which hid the treat’s odor. A second cup contained sand with a different scent but no treat. The researchers could change the cage’s environment by affixing colored cutouts to the transparent cage walls, adding a textured floor and making other modifications.

The normal mice learned that in the first environment, the chocolate was linked to the first scent. When the researchers changed to a second environment, the mice learned to find the chocolate using the second scent.

Once the mice were trained, an area of the brain called the hippocampus was injected with a genetically engineered virus that selectively cut out the NR1 gene. NR1 produces a protein that is critical for molding nerve messages in an area of the hippocampus called the CA3, which is associated with distinguishing complex patterns.

It is this molding that underlies the hippocampal-dependent learning and memory that is needed to distinguish the complex patterns.

The researchers then attempted to train the mice in memory tasks with new scents and new environments, but the animals lacking the gene couldn’t learn. The control group, which received an injection that doesn’t cut out NR1, learned as quickly as before.

This shows that the treated animals couldn’t react properly to situational cues, which also happens in people with schizophrenia, Dr. Greene said.

The researchers hope to see in future studies if similar small changes to nearby brain regions involved in learning and memory result in the same kind of problems.

"In addition, we want to use a similar task in humans to that used in this study to see if patients with schizophrenia have similar deficits in cognition as we observed in our experimental mice," Dr. Greene said. "This will help determine whether our genetically altered animals provide a good model of the psychosis associated with schizophrenia."

Former UT Southwestern researchers involved in the study were Dr. Tarek Rajji, a psychiatry resident now at the University of Pittsburgh, and Dr. David Chapman, a postdoctoral fellow now at UCB Pharma. Dr. Howard Eichenbaum of Boston University also participated in the study.

The work was supported by the National Institute of Mental Health and the Department of Veterans Affairs.

Aline McKenzie | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>