Featured Research

from universities, journals, and other organizations

Where's The Cheese? Researchers Discover 'Episodic-like' Memory In Rats

Date:
July 11, 2006
Source:
University of Georgia
Summary:
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.

UGA researchers Jonathon Crystal and Stephanie Babb 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.
Credit: Jonathon Crystal

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.)

The research was supported by grants from the National Institute of Mental Health.


Story Source:

The above story is based on materials provided by University of Georgia. Note: Materials may be edited for content and length.


Cite This Page:

University of Georgia. "Where's The Cheese? Researchers Discover 'Episodic-like' Memory In Rats." ScienceDaily. ScienceDaily, 11 July 2006. <www.sciencedaily.com/releases/2006/07/060711094623.htm>.
University of Georgia. (2006, July 11). Where's The Cheese? Researchers Discover 'Episodic-like' Memory In Rats. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2006/07/060711094623.htm
University of Georgia. "Where's The Cheese? Researchers Discover 'Episodic-like' Memory In Rats." ScienceDaily. www.sciencedaily.com/releases/2006/07/060711094623.htm (accessed July 23, 2014).

Share This




More Mind & Brain News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Do Obese Women Have 'Food Learning Impairment'?

Do Obese Women Have 'Food Learning Impairment'?

Newsy (July 18, 2014) Yale researchers tested 135 men and women, and it was only obese women who were deemed to have "impaired associative learning." Video provided by Newsy
Powered by NewsLook.com
Does Mixing Alcohol and Energy Drinks Boost Urge To Drink?

Does Mixing Alcohol and Energy Drinks Boost Urge To Drink?

Newsy (July 18, 2014) A new study suggests that mixing alcohol with energy drinks makes you want to keep the party going. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins