Remembering your fun times can help you feel better. Positive memories can be really powerful for your mental well-being. It will not only help you better regulate your emotions. They can also have a positive effect on depression resulting from stress.
A group of scientists conducted an experiment on laboratory mice to investigate this effect. They found that artificially reactivating good memories can suppress stress-induced depression. Let’s take a closer look at their findings.
Artificially induced positive memories
This study showed the link between positive memories and depression. It was published in the journal Nature. Researchers from the RIKEN-MIT Center for Neural Circuit Genetics, the RIKEN Brain Science Institute in Japan, and the Massachusetts Institute of Technology (MIT) conducted this study.
They conducted the research in the Tonegawa Laboratory. Susumu Tonegawa is the director of the RIKEN Brain Science Institute and a professor at MIT. In 1987 he was awarded the Nobel Prize for his discovery of the diversity in antibodies. The study discussed in this article addresses the issue of whether a positive memory can override a negative one.
To answer this question, the researchers used genetic engineering. The goal was to create mice in which they could mark memory cells while creating memories.
Afterwards, they would then be able to reactivate these memories with an optical fiber. This optical fiber emits a blue light and is implanted in the same place. The research team was then able to activate the memory cells created during previous experiences.
To test the system, they exposed male mice to a positive experience. In this case, seeing a female mouse was the positive experience. They then created a memory of this event. Then they exposed the mice to a stressful experience that led to a state similar to depression.
While the mice were depressed, the researchers used the lights to stimulate the dentate gyrus (or serrated convolution, is part of the hippocampus) in some mice. In this way they reactivated the cells of the positive experience.
Storing positive memories is essential
To their surprise, there was an improvement in the depressed mood in the mice. In addition, they also found that two other brain regions interacted with the dentate gyrus to reactivate positive memories: the nucleus accumbens and the basolateral nucleus of the amygdala.
On the other hand , the researchers also wanted to find out whether this form of recovery from depression could involve permanent changes in the brain circuits. In other words, they wanted to know if this would last even without the light stimulation.
With this goal in mind, the scientists administered chronic light therapy to the dentate gyrus for more than five days. They found that this offered a guarantee for a lasting re-activation of the positive memories.
The mice that received this therapy were resistant to the negative effects of stress-induced depression. This suggests that storing positive experiences in memory can help improve mood.
So we can use these memories to suppress or override the negative effects of stress. This could mean a new way to control the mood.
What do these results mean?
The results of this study have important implications for mood disorders such as depression. In addition, the findings also provide more insight into stress.
Scientists still do not fully understand the interaction between positive or negative experiences and the corresponding memories. Nevertheless, these findings open the way to new fields of interest in the treatment of mood disorders.
The research suggests that positive memories can alter the effects of stress-induced depression. However, the researchers also stated that it is still too early to draw conclusions.