Navigation Links
U discovery gives insight into brain 'replay' process
Date:3/11/2010

MINNEAPOLIS / ST. PAUL (March 11, 2010) The hippocampus, a part of the brain essential for memory, has long been known to "replay" recently experienced events. Previously, replay was believed to be a simple process of reviewing recent experiences in order to help consolidate them into long-term memory. However, University of Minnesota Medical School researcher A. David Redish, Ph.D., along with his colleagues Anoopum Gupta and David S. Touretzky, Ph.D., from the Center for the Neural Basis of Cognition at Carnegie Mellon University, and Matthijs van der Meer, Ph.D., also at the University of Minnesota, have discovered that the replay function of the hippocampus is actually a much more complex, cognitive process.

This discovery gives insight into the decision-making process and Redish hopes that this insight will help researchers learn more about what is happening in the brain when this decision-making process goes wrong.

By studying brain activity in rats, Redish, Gupta, and colleagues discovered that the information played out during this replay process depends on the task the animal is facing. They found that it was not the more recent experiences that were played back in the hippocampus, but instead, the animals were most frequently playing back the experiences they had encountered the least. They also discovered that some of the sequences played out by the animal were ones they had never before experienced. These observations suggest that this hippocampal process plays an important role in an animal's active learning process and may also play a role in maintaining the animal's internal representation of the world, or its cognitive map.

"The point of the cognitive map is flexibility. It gives animals the ability to plan novel paths within their environment," said Redish. "This replay process may be an animal's way of learning how the world is interconnected, so it can plan new routes or paths."

Redish and his team have been studying decision-making in rats by putting electrode "hats" on the animals and recording their brain activity. The hats detect when individual neurons in the brain fire. Certain neurons, called place cells, fire in response to the animal's current physical location and create the animal's internal, cognitive map of their environment. Through their study of the animal's brain activity, Redish and his team can identify where the rat is located simply by observing which place cells are firing.

This mapping process was key to the team's understanding of the animal's replay process. During replay, neurons fire indicating other locations on the maze rather than the location the rat actually is, indicating that the animal is processing information about other locations. On a task with two behavioral sequences, A and B, the researchers found that the animals would replay sequence B more often, even when they spent most of their time running sequence A. In other words, the researchers found that the rats were most likely to replay the path they had experienced less often. This suggests that replay is not just a function of helping an animal remember what it has experienced most frequently or most recently, but an important function in helping it map its whole environment.

During the replay process, Redish, Gupta, and colleagues also were able to observe the animal making connections between paths that it had never physically traveled before. For example, if the animal had physically traveled from point A to point B, and from point B to point C, but never from point A to point C, they observed the single sequence A to B to C during the replay process, implying that the rat's brain was able to make the connection between points A and C on its internal map. This further indicates that replay plays a role in helping an animal learn and maintain the entire map of its environment and make connections within it. The rats were not just reviewing recent experience to move it to long-term memory.

This is important because brain cognition and the human decision-making process are poorly understood.

"Before we can understand how this process goes wrong in people with diseases such as addiction or Alzheimer's, we first need to understand how cognitive connections are made in the brain and how humans make decisions in relation to their internal, cognitive map. Once we have an understanding of how things work in normal brain processing, we can understand where they can break. And then we can understand what we can do to try to fix them," Redish said.

The discovery of this mechanism in rats gives important insight into their decision-making process and through more research, Redish hopes to further understand how this mechanism works.


'/>"/>

Contact: Laura Stroup
stro0481@umn.edu
612-624-9912
University of Minnesota
Source:Eurekalert

Related medicine news :

1. Co-Creator of Six Sigma Unveils “The Great Discovery” ... the 4th Generation of Six Sigma
2. Effective prostate cancer treatment discovery
3. SeqWright Advances Genomic Discovery With Isilon IQ
4. New discovery: Plaice are spotted (on the inside)
5. UCSF enters drug discovery agreement with Genentech
6. UCSF Enters Drug Discovery Agreement with Genentech
7. Discovery Health and National Organization for Rare Disorders Partner for Second Annual Rare Disease Day With the Premiere of the Special DISEASE DETECTIVES
8. Discovery points way for new treatment for aneurysms: UBC-Providence Research
9. Discovery of mechanism in brain cell injury in Huntingtons offers new treatment approaches
10. Discovery Links Genes to Pancreatic Cancer
11. Discovery of epigenetic memory during breast cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/2/2016)... ... 2016 , ... Center for Autism and Related Disorders (CARD) Portland today announced ... disorder (ASD) and other developmental disabilities. The group, which is being launched with the ... the opportunity to share stories and advice, seek help, and continue their education on ...
(Date:12/2/2016)... ... 2016 , ... U.S. Surgeon General, Dr. Vivek Murthy, graces the cover of ... was inspired to practice medicine at an early age by his father, who was ... diagnoses and prescribing medicine,” he states. “It is about building relationships with people; relationships ...
(Date:12/2/2016)... ... December 02, 2016 , ... ... two ostomy patients, standing as living proof that attitude and determination can combine ... and issues that spike around the holidays. This campaign will offer patients a ...
(Date:12/2/2016)... ... December 02, 2016 , ... More than half of American teens report losing ... report speaking with their child about sex related topics, less than 60 percent spoke ... proud to announce the launch of its second edition of the “Sexual Wellness” campaign, ...
(Date:12/2/2016)... ... 02, 2016 , ... CloudLIMS.com, a class-leading provider of Laboratory ... CloudLIMS Lite helps biobanks, clinical, research and testing laboratories keep track of their ... version is a faster and a more efficient product, allowing batch processing of ...
Breaking Medicine News(10 mins):
(Date:12/2/2016)... -- UCB is pleased to announce that 12 scientific abstracts have ... American Epilepsy Society (AES) Annual Meeting, which takes place ... USA. 1-12 Data being presented include ... ® (lacosamide) CV and BRIVIACT ® (brivaracetam) CV. ... state of the union of epilepsy care and antiepileptic drugs ...
(Date:12/2/2016)... -- Allergan plc (NYSE: AGN ), a leading ... announced Accelerated Share Repurchase (ASR) Program. Logo - ... , ... announced, the Company entered into a variable tenor ASR arrangement ... $10 billion of its ordinary shares. Approximately 40.5 million shares ...
(Date:11/30/2016)... , Nov 30, 2016 Research and ... Intracranial Pressure Monitoring Devices 2017 - MedCore" report to their offering. ... , , ... brain and the skull. In healthy individuals, it is circulated though the ... are cases where the amount of CSF surrounding the brain changes significantly. ...
Breaking Medicine Technology: