NIH-funded scientists have detected direct evidence of individual brain cells signaling the formation of new memories. Neurons they call "changing cells" in the hippocampus, the brain's memory hub, emit telltale signals as a monkey learns an associative memory task, the researchers have discovered. While past studies established that new associative memories such as learning the name of a new acquaintance -- can't be learned without the hippocampus, none had pinpointed such smoking guns of memory acquisition at the neural level. Wendy Suzuki, Ph.D., New York University (NYU), and colleagues, report their findings in the June 6, 2003 Science.

"When hippocampal cells undergo these striking changes in neuronal activity, its like watching a new memory being born," explained Suzuki, whose research was funded by the National Institute of Mental Health (NIMH) and the National Institute on Drug Abuse (NIDA). "The key to detecting 'changing cells' was to keep the task simple so that the monkeys could easily learn multiple new associations within a single recording session."

The researchers measured activity of individual neurons in the hippocampus as two monkeys formed new associative memories while playing a computer game. The monkey had to gaze at one of four identical targets superimposed on a complex visual scene to win a juice reward. For example, white dots appeared at four locations over a picture of a gorilla in a forest. The animals learned, through trial and error, which location was associated with the reward for each new scene. Eye-tracking technology detected if the animal was fixated on the correct dot and the reward was dispensed. Monkeys learned 2-4 new associations during each recording session. It took about a dozen trials to establish the memory for each scene.

Among 89 neurons that responded to the scenes, the researchers discovered a subset of 25 "changing cells" whose increase or decrease in activity paralleled learni
'"/>

Contact: Jules Asher
NIMHpress@nih.gov
301-443-4536
NIH/National Institute of Mental Health
5-Jun-2003

Page: 1 2
Related biology news :

1. Brown research reveals key insight into memory-making
2. Wrapping a memory with an experience, capacity for recollection detected in non-human species
3. Forgetting, reminding, and remembering: The retrieval of lost spatial memory
4. Mutant mice lead to memory insights
5. Protein believed to control formation of memory identified by Scripps & UCSD scientists
6. Alzheimers may leave some forms of memory intact
7. Study in flies allows researchers to visualize formation of a memory
8. Brain signal predicts working memory prowess
9. Lack of specific brain protein causes marked deficits in learning, memory
10. Scientists discover why not enough choline results in fewer brain cells, poorer memory
11. Flies offer clues to anesthesia-resistant memory