Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UGA researchers discover 'episodic-like' memory in rats

11.07.2006
Animal model could assist Alzheimer's disease research

Human memory is a mental scrapbook, filled with moments of luminous happiness or unforgettable sorrow. We remember the day we said "I do," and the first glimpses of our children and grandchildren. But among the elderly, pages often go missing from the scrapbooks of their memory, and those with Alzheimer's disease or amnesia may have nothing left of their memorable lives at all.

Researchers have long sought animal models to help them study memory and have repeatedly asked one question: Are humans the only ones who remember unique, personal past experiences, or can animals do it, too? Now, researchers from the University of Georgia are closer to solving the problem.

Psychologists from UGA report in the new issue of Current Biology that laboratory rats have a detailed representation of remembered events and therefore also likely have episodic-like memory. The finding gives researchers an animal model that could help in understanding how humans with Alzheimer's or amnesia lose their memory.

"Understanding whether animals have this kind of memory has been a challenge for years," said Jonathon Crystal, an associate professor of psychology who directed the research. His co-author on the paper was Stephanie Babb, a former Ph.D. student at UGA and now a post-doctoral fellow at the University of Texas Medical School in Houston. "What we have always needed is a model animal with which we can ask questions about the neural basis of episodic memory."

The new findings could be a first step toward testing new drugs in rats for humans with diseases such as Alzheimer's or amnesia.

Crystal and Babb used a radial maze, an eight-armed device with a central hub, in which laboratory rats were able to search for specific foods and relate their presence or absence to remembered cues. Each arm has a door at the junction with the central hub so the rats can choose which of the eight arms to go into.

"If rats have specific information about the content of events they experienced in the past, together with the knowledge of when and where those events occurred, then they should adjust their behavior to the temporal and spatial constraints of food availability," said Crystal. "To address this question, we trained rats to discriminate what, where and when they encountered food."

To do this, they provided rats with access to locations baited with distinctive flavors such as grape or raspberry and non-distinctive flavors such as the chow the animals are usually fed. The researchers then replenished the food locations with distinctive flavors after a long but not a short delay and didn't replenish the locations with non-distinctive flavors at all.

They further complicated the rats' choices by either pre-feeding them with the distinctive flavor so they would be full or by pairing it with nauseating lithium chloride. This "devalued" selected distinctive flavors. To the researchers' surprise, the rats then selectively decreased their return visits to the "devalued distinctive flavor" while continuing to return regularly to the flavors that hadn't been so devalued.

By replicating the tests, the psychologists were able to show conclusively that the rats possessed "episodic-like memory," something that had never been proved in any laboratory mammal, though such behavior has been demonstrated in scrub jays.

Earlier research by Crystal and numerous other researchers has shown that rats don't navigate well by smell, and the UGA experiments were designed to rule out other reasons why the rats returned to food sources in the radial maze at certain times.

"The most surprising thing to us was that the rats solved the problem," said Crystal. "People have been trying to document episodic-like memory in rats for a while, and they haven't succeeded. This is basic science that has the potential to translate into the clinical realm." (Other scientists have also long attempted to prove such memory in monkeys and have not yet succeeded in showing that, either.)

Kim Carlyle | EurekAlert!
Further information:
http://www.uga.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>