Recording bad dreams in rats

September 12, 2017 by Bob Yirka report
Credit: CC0 Public Domain

A trio of researchers working at New York University Neuroscience Institute has recorded what appear to be bad dreams in the brains of rats as they sleep. In their paper published in the journal Nature Neuroscience, Gabrielle Girardeau, Ingrid Inema and György Buzsáki describe experiments they carried out with rats and what they found.

Bad dreams or nightmares, it has been noted, often happen to people after they experience something bad in real life, though the responsible mechanisms in the are still murky at best. To learn more about how they may work, the researchers conducted experiments with rats meant to conjure and then monitored their to see what would happen.

The experiments consisted of teaching rats to traverse a maze and then giving them a bad experience along the way—a puff of air in the face from a keyboard cleaner. The researchers recorded brain activity for the rats throughout the experiments. They noted that both hippocampi became active during the times when the rats were engaged in learning how to traverse the maze. The team was even able to follow the sequence of neurons that fired as a given rat progressed through a maze after learning its way through. They found that when the rat was suddenly "scared" by the blast of air, the amygdalas both became active as well, which was not surprising—prior research has shown it is the part of the brain that becomes involved when processing emotional information.

The researchers continued to monitor the as they slept and report that they were able to follow along as a rat ran through a maze in its dreams—the same sequence of neurons fired as had done so while the rat was actually carrying out the activity in real life. Then, at the point in the sequence where the rat was blasted with the air, the amygdalas lit up once again, suggesting the rat was reliving the unpleasant experience in its —the dream had suddenly become a bad dream or a nightmare.

The researchers readily acknowledge that they really can't say what the are experiencing, but suggest their findings have opened the door for further research with people—and possibly a much better understanding of the processes involved in human nightmares.

Explore further: Researchers devise a way to manipulate a rat's dreams

More information: Gabrielle Girardeau et al. Reactivations of emotional memory in the hippocampus–amygdala system during sleep, Nature Neuroscience (2017). DOI: 10.1038/nn.4637

Abstract
The consolidation of context-dependent emotional memory requires communication between the hippocampus and the basolateral amygdala (BLA), but the mechanisms of this process are unknown. We recorded neuronal ensembles in the hippocampus and BLA while rats learned the location of an aversive air puff on a linear track, as well as during sleep before and after training. We found coordinated reactivations between the hippocampus and the BLA during non-REM sleep following training. These reactivations peaked during hippocampal sharp wave–ripples (SPW-Rs) and involved a subgroup of BLA cells positively modulated during hippocampal SPW-Rs. Notably, reactivation was stronger for the hippocampus–BLA correlation patterns representing the run direction that involved the air puff than for the 'safe' direction. These findings suggest that consolidation of contextual emotional memory occurs during ripple-reactivation of hippocampus–amygdala circuits.

Related Stories

Researchers devise a way to manipulate a rat's dreams

September 6, 2012
(Medical Xpress)—Cognitive scientists working at MIT have devised a means for not only altering the dreams of rats, but of demonstrating a way of testing what they've achieved, offering evidence that it can be done, and ...

New research suggests we also dream during non-REM sleep cycles

April 11, 2017
(Medical Xpress)—A team of researchers with members from institutions in the U.S., Italy and Switzerland has found evidence that suggests people have dreams during both REM and non-REM sleep cycles. In their paper published ...

Study reveals how learning in the present shapes future learning

April 6, 2017
Neurons in the prefrontal cortex "teach" neurons in the hippocampus to "learn" rules that distinguish memory-based predictions in otherwise identical situations, suggesting that learning in the present helps guide learning ...

Recommended for you

Investigating patterns of degeneration in Alzheimer's disease

November 17, 2017
Alzheimer's disease (AD) is known to cause memory loss and cognitive decline, but other functions of the brain can remain intact. The reasons cells in some brain regions degenerate while others are protected is largely unknown. ...

Study may point to new treatment approach for ASD

November 17, 2017
Using sophisticated genome mining and gene manipulation techniques, researchers at Vanderbilt University Medical Center (VUMC) have solved a mystery that could lead to a new treatment approach for autism spectrum disorder ...

Paraplegic rats walk and regain feeling after stem cell treatment

November 16, 2017
Engineered tissue containing human stem cells has allowed paraplegic rats to walk independently and regain sensory perception. The implanted rats also show some degree of healing in their spinal cords. The research, published ...

Brain implant tested in human patients found to improve memory recall

November 15, 2017
(Medical Xpress)—A team of researchers with the University of Southern California and the Wake Forest School of Medicine has conducted experiments involving implanting electrodes into the brains of human volunteers to see ...

Researchers identify potential mediator for social memory formation

November 15, 2017
Research by a group of scientists at the Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine) have discovered that a tiny brain region plays a critical role in the formation ...

Improving clinical trials with machine learning

November 15, 2017
Machine learning could improve our ability to determine whether a new drug works in the brain, potentially enabling researchers to detect drug effects that would be missed entirely by conventional statistical tests, finds ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.