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 Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>