image: Fluorescent-tagged cells in the hippocampus (A), including engram cells (D). view more
Credit: Zhang et al., JNeurosci 2019
Physical manifestations of negative memories in the hippocampus could underlie cognitive symptoms of depression, according to research in mice published in JNeurosci. Inhibiting these manifestations could be a future treatment route.
Groups of neurons that are activated after an experience are thought to be the physical representation of memory. These so-called engrams in the hippocampus could be involved in depression, which is characterized by impaired recall of positive memories and increased recall of negative memories.
In a mouse model of depression, Tak Pan Wong and colleagues at Douglas Hospital Research Centre tagged the engrams that formed after mice experienced social stress and examined their social avoidance behavior. Even though all mice experienced the same stressor, only some displayed depression behaviors, indicating a predisposition to developing depression.
The depression-prone mice displayed higher concentrations of engram cells compared to the less susceptible mice, and the density of the cells correlated with the level of social avoidance behavior. Activating the engram cells increased social avoidance behavior while suppressing the cells decreased it, suggesting a role in the cognitive symptoms of depression.
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Manuscript title*: Negative Memory Engrams in the Hippocampus Enhance the Susceptibility to Chronic Social Defeat Stress
*A preprint of this manuscript is available on bioRxiv
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About JNeurosci
JNeurosci, the Society for Neuroscience's first journal, was launched in 1981 as a means to communicate the findings of the highest quality neuroscience research to the growing field. Today, the journal remains committed to publishing cutting-edge neuroscience that will have an immediate and lasting scientific impact, while responding to authors' changing publishing needs, representing breadth of the field and diversity in authorship.
About The Society for Neuroscience
The Society for Neuroscience is the world's largest organization of scientists and physicians devoted to understanding the brain and nervous system. The nonprofit organization, founded in 1969, now has nearly 37,000 members in more than 90 countries and over 130 chapters worldwide.