Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Smart' mice teach scientists about learning process, brain disorders

30.05.2007
Mice genetically engineered to lack a single enzyme in their brains are more adept at learning than their normal cousins, and are quicker to figure out that their environment has changed, a team led by researchers at UT Southwestern Medical Center has found.

The results, appearing today in the online edition of the journal Nature Neuroscience, reveal a new mechanism of learning in the brain, which might serve in humans as a target for treating disorders such as post-traumatic stress disorder, Alzheimer’s disease or drug addiction, the researchers said.

“It’s pretty rare that you make mice ‘smarter,’ so there are a lot of cognitive implications,” said Dr. James Bibb, assistant professor of psychiatry and the study’s senior author.

“Everything is more meaningful to these mice,” he said. “The increase in sensitivity to their surroundings seems to have made them smarter.”

The engineered mice were more adept at learning to navigate a water maze and remembering that being in a certain box involves a mild shock. Equally important, Dr. Bibb said, when a situtation changed, such as the water maze being rearranged, the engineered mice were much faster to realize that things were different and work out the new route.

... more about:
»BIBB »Cdk5 »Psychiatry »disorder

Dr. Bibb cautioned that while the mice learn faster, studies on the long-term effects of deleting the enzyme, called Cdk5, from the brain are continuing.

The group is also beginning a search for drugs that might create the same effects without genetic manipulation and monitoring the animals’ health and behavior over time.

The findings may have applications in treating post-traumatic stress disorder, where getting a patient to learn that a once-threatening situation no longer poses a danger is a major goal.

In addition, Cdk5 is heavily implicated in Alzheimer’s disease and addiction to drugs of abuse, so understanding how the enzyme affects the brain and behavior might aid in the development of new treatments for these and other conditions, Dr. Bibb said.

The key in this study was being able to “knock out” the gene for Cdk5 only in the brain, and only when the mice were adults. This technique, only recently developed and called conditional knockout, allows much more sophisticated experiments than traditional knockout, which entirely eliminates the gene.

“Being able to turn a gene off throughout a brain is a really advanced thing to do,” Dr. Bibb said. “It’s been shown that it can be done, but we put the system together and actually applied it.”

Normally, Cdk5 works with another enzyme to break up a molecule called NR2B, which is found in nerve-cell membranes and stimulates the cell to fire when a nerve-cell-signaling molecule, or neurotransmitter, binds to it. NR2B previously has been implicated in the early stages of learning.

The new research showed that when Cdk5 is removed from the brain, the levels of NR2B significantly increase, and the mice are primed to learn, Dr. Bibb said.

“We made the animals ‘smarter,’ but in doing so and applying this technology, we also found biochemical targets that hold promise for future treatments of a variety of cognitive disorders,” he said.

The researchers also recorded nerve-cell firings in the hippocampus, an area of the brain associated with learning. Hippocampus slices from the knock-out mice responded much more strongly to an electrical stimulation, supporting the finding that the mice were more prepared to learn.

Other UT Southwestern researchers involved in the study were Ammar Hawasli, David Benavides and Chan Nguyen, students in the Medical Scientist Training Program; Dr. Janice Kansy, instructor in psychiatry; Dr. Kanehiro Hayashi, postdoctoral researcher in psychiatry; Dr. Craig Powell, assistant professor of neurology; and Dr. Donald Cooper, assistant professor of psychiatry. Researchers from the Institut de Génétique et de Biologie Moléculaire et Cellulaire in Strausbourg, France, and The Rockefeller University also participated.

The work was supported by the National Institute on Drug Abuse, the National Institutes of Health, NARSAD, the National Institute of Mental Health and the Ella McFadden Charitable Trust Fund at the Southwestern Medical Foundation.

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

Further reports about: BIBB Cdk5 Psychiatry disorder

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>