Summary: Researchers have successfully reactivated storage wires in animals, causing them to get shelter even when there was no one around them. By stimulating neurons linked to geographical memory, the crew activated a past recollection of shelter-seeking habits.
This study provides insight into how storage circuits function in the mind and may aid in the development of strategies to stop memory loss in neurodegenerative diseases. The findings provide convincing insights into how to engineer or reactivate memory circuits to maintain brain function in memory-deficient situations.
Important Information:
- Reactivating neurons led mice to seek shelter where there was n’t one.
- Geographic recollection that was related to previous experiences was a part of the memory circuit.
- In degenerative diseases, this research may provide new solutions for storage loss.
Origin: Johns Hopkins University
Researchers at Johns Hopkins Medical claim to have successfully reactivated a certain memory loop in mice, causing them to seek out shelter when there is no such thing as shelter.
The experts say the investigation, published Sept. 27 in , Nature Neuroscience, improvements knowledge of how reminiscences are structured in the vertebrate mind.
The findings may one day lead to novel ways to stop or slow down the memory loss that comes with Alzheimer’s and other neurological diseases.
Specifically, the team found that stimulating neurons in two areas of mouse brains — the nucleus accumbens, also known as the brain’s “pleasure center” responsible for relaying dopamine-dependent behaviors, and the dorsal periaqueductal gray (dPAG ), responsible for defensive behavior — reactivated a” spatial memory” and caused the mice to seek shelter.
According to senior author, Hyungbae Kwon, Ph. D.,” When we artificially reactivate those memory circuits in the brain, it triggers the mouse to do the same thing it did naturally, even without the fear stimuli that lead them to seek shelter first,” Dr., Johns Hopkins University School of Medicine associate professor of neuroscience.
The experts say they aimed to chart out which areas of the brain are responsible for navigating one’s area, a high-level mental work among animals, including humans.
Therefore, these experiments, which tested whether for cognitive brain functions may be replayed haphazardly, may have programs in understanding how another mammals behave, perceive and sense their culture.
In the new tests, the researchers first gave laboratory mice the opportunity to explore their surroundings inside a container with a house in the edge. The group placed a series of visual signals, including rectangles, circles and stripes in various colors, to support the mice locate the house based on local landmarks. The animals acclimated to the place for seven moments, entering and exiting the house.
The researchers then added a visual or audio looming sign to encourage them to find shelter, creating a geographical remembrance in response to their site and the visual cues.
To selectively tag shelter memory neurons, the researchers used a light-activated gene-expression switching system called Cal-light, which Kwon , developed in 2017.
Once the researchers found these neurons in the nucleus accumbens, they started the expression of the genes that were related to them, reactivating the shelter-seeking memory in mice while also activating dPAG neurons.
When neither the original threat nor the shelter were present, the mice then searched out the area of the box where the shelter had once been.
To determine whether switching on neurons in just one area of the brain would lead to this behavior, the researchers first selectively activated neurons in the nucleus accumbens and then separately, in the dPAG.
” Surprisingly, we found that the mice did not seek out shelter when we activated neurons in the nucleus accumbens alone”, Kwon says.
While “wiring on the dPAG neurons caused the mice to react at random, but did not specifically direct them to the place where they had previously sought refuge.”
Kwon says the Cal-light system made it possible to map out memory on a cellular level by allowing us to select a particular brain function.  ,
Kwon claims that this research could eventually lay the groundwork for engineering or reactivating memory circuits in people with Alzheimer’s.  ,
He claims that if we can understand the structure of memory at the macro-level, we might be able to develop more potent strategies to stop or slow down neurodegenerative diseases.
The researchers claim that they can learn about brain-wide memory by selectively tagging and reactivating neurons with various functions in various brain regions that lead to other particular behaviors.
Understanding how all of these memory circuits function together will help us better understand brain function, he says.
Other researchers involved in the study are Kanghoon Jung, Sarah Krüssel, Sooyeon Yoo, Benjamin Burke, Nicholas Schappaugh, Youngjin Choi and Seth Blackshaw of Johns Hopkins, Myungmo An of the Max Planck Florida Institute for Neuroscience, and Zirong Gu and Rui M. Costa of the Zuckerman Mind Brain Behavior Institute at Columbia University and the Allen Institute.
Funding: Funding for this work was provided by the Max Planck Florida Institute for Neuroscience, a National Alliance for Research on Schizophrenia and Depression Young Investigator Grant and National Institutes of Health Grants R01MH107460, 5U19NS104649, K99 NS119788, DK108230 and DP1MH119428.
About this news about neuroscience and memory research
Author: Alexandria Carolan
Source: Johns Hopkins University
Contact: Alexandria Carolan – Johns Hopkins University
Image: The image is credited to Kanghoon Jung
Original Research: Open access.
” Dopamine-mediated formation of a memory module in the nucleus accumbens for goal-directed navigation” by Kanghoon Jung et al. Nature Neuroscience
Abstract
Dopamine-mediated formation of a memory module in the nucleus accumbens for goal-directed navigation
Navigation is effectively guided by spatial memories toward the desired destinations. The neuronal and circuitry that underlie the goal location encoding and its conversion into goal-directed navigation are still a mystery.
Here we demonstrate that mice rapidly form a spatial memory of a shelter during shelter experiences, guiding escape behavior toward the goal location—a shelter—when under threat.
The ventral tegmental area’s dopaminergic neurons, which protrude to the nucleus accumbens ( NAc ), encode safety signals related to the shelter.
Phasic dopamine signals that are optically induced are sufficient to establish a place memory that controls escape navigation.
A subpopulation of NAc neurons in a converging dopaminergic and hippocampal glutamatergic inputs mediates the formation of a goal-related memory during shelter experiences.
Artificial co-activation of this goal-related NAc ensemble with neurons in the dorsal periaqueductal gray was sufficient to trigger memory-guided, rather than random, escape behavior.
These findings provide a causal link between memory and goal-directed action in cognitive circuit modules.
