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

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.

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.
'"/>

Source:UT Southwestern Medical Center


Related biology news :

1. Smart nanoprobes light up disease
2. Smart genetic therapy helps the body to heal itself
3. First demonstration of teaching in non-human animals
4. APS lecturer shows rare video of teacher-student immune cell interactions in live animal
5. New book uses ABCs to teach children microbiology
6. Wisconsin scientists grow critical nerve cells
7. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
8. UAB scientists discover the origin of a mysterious physical force
9. Fox Chase Cancer Center scientists identify immune-system mutation
10. Weizmann Institute scientists develop a new approach for directing treatment to metastasized prostate cancer in the bones.
11. U-M scientists find genes that control growth of common skin cancer

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/19/2017)... April 19, 2017 The global ... landscape is marked by the presence of several large ... held by five major players - 3M Cogent, NEC ... accounted for nearly 61% of the global military biometric ... in the global military biometrics market boast global presence, ...
(Date:4/11/2017)... 11, 2017 Crossmatch®, a globally-recognized leader ... today announced that it has been awarded a ... Activity (IARPA) to develop next-generation Presentation Attack Detection ... "Innovation has been a driving force within Crossmatch ... allow us to innovate and develop new technologies ...
(Date:4/5/2017)... 5, 2017  The Allen Institute for Cell Science ... a one-of-a-kind portal and dynamic digital window into the ... the first application of deep learning to create predictive ... lines and a growing suite of powerful tools. The ... and future publicly available resources created and shared by ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... The CRISPR-Cas9 ... overexpression experiments and avoiding the use of exogenous expression plasmids. The simplicity of ... performing systematic gain-of-function studies. , This complement to loss-of-function studies, such as ...
(Date:10/11/2017)... ... October 11, 2017 , ... Proscia Inc ... hosting a Webinar titled, “Pathology is going digital. Is your lab ready?” with ... adoption best practices and how Proscia improves lab economics and realizes an increase ...
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased emissions are ... 5.5 million people each year. Especially those living in larger cities are affected by ... in one of the most pollution-affected countries globally - decided to take action. , ...
(Date:10/10/2017)... , ... October 10, 2017 , ... San Diego-based team ... its corporate rebranding initiative announced today. The bold new look is part of ... the company moves into a significant growth period. , It will also expand its ...
Breaking Biology Technology: