Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hamster study shows how our brains recognize other individuals

09.03.2006


Imagine seeing a former high school classmate you always wanted to know better. Then imagine seeing that kid who used to push you in the hallways. Do you react differently? What happens in your brain during these encounters?



In fact, different areas of the brain react differently when recognizing others, depending on the emotions attached to the memory, a team of Cornell University research psychologists has found. The team, led by professor of psychology Robert Johnston, has been conducting experiments to study individual recognition.

But rather than crash high school reunions with an MRI machine in tow, the researchers stayed in their laboratory and created social encounters between golden hamsters. Then they examined the animals’ brains for evidence of those encounters.


Last year Johnston’s team conducted the first experiment to demonstrate the neural basis of individual recognition in hamsters and identify which areas of the brain play a role. The results were published in the Dec. 7, 2005, issue of the Journal of Neuroscience.

Better understanding these mechanisms, Johnston said, may be of central importance in treating certain forms of autism, Asperger syndrome, psychopathy and social anxiety disorders.

"This ability to recognize individuals underlies social behavior in virtually all vertebrates and some invertebrates as well," explained Johnston. "Humans clearly have an incredible ability to recognize, remember and store huge amounts of information about individuals -- even individuals we have never actually met. This ability is the core of circuits that one might call the social brain."

Johnston’s team uses hamsters to study recognition because their brains are strikingly similar to ours. "They are more sophisticated than you might think," he noted.

In the latest experiment, a male hamster encountered two individuals that he knew equally well but had different interactions with the previous day: a male that defeated him in a fight and a male that he had never fought. The encounters mimicked those that occur in the wild.

The hamster fled from the winning male but was attracted to the neutral male -- suggesting that he both recognized the individuals and remembered his experiences with them.

An hour later, the researchers removed the hamster’s breath-mint-sized brain and injected it with antibodies and enzymes. The antibodies bond to specific proteins produced by recently active brain cells, and the enzymes convert chemicals in the cells into colored dyes, leaving behind a map of where the action was. This technique, called immunohistochemistry, is also used to diagnose cancerous cells in humans.

Next the brain was frozen with dry ice, shaved into very thin slices using a miniature slow-moving guillotine and then studied under a microscope to determine where the dyes were activated.

"Functional MRIs provide similar information from human brains, but those images are relatively fuzzy and lack the spatial resolution necessary for small animals," explained Johnston. "With immunohistochemistry, on the other hand, we can see each individual cell that was activated."

The researchers found activity in the brain’s anterior dorsal hippocampus and amygdala, among other areas. They then repeated the experiment with another hamster whose anterior dorsal hippocampus was numbed with lidocaine, a local anesthetic, and found that the animal did not avoid the individual who had defeated him.

"It showed us that this region is necessary for recognition memory," said Johnston. "The hippocampus has also been implicated for recognition memory in humans."

Although hamsters recognize individuals by smell, whereas humans use largely sight and sound, Johnston said that the underlying mechanism is the same. The other authors of the Neuroscience article are first author and former Cornell graduate student Wen-Sung Lai ’03, graduate student Leora Ramiro and former undergraduate Helena Yu ’03. The National Institute of Mental Health supported the research.

Blaine Friedlander | EurekAlert!
Further information:
http://www.cornell.edu

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | 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: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>