To Forget or to Remember? Memory Depends on Subtle Brain Signals, Scientists Find
Source: The Scripps Research Institute
Summary: In a new study, researchers have detailed the complex biochemical mechanisms how brain stores scent-associated memories and erase unnecessary memories.
In many ways, the process of forgetting and remembering are similar. The odor-associated learning in fruit fly models, wherein both, the memories of storing and erasure involves activation of dopamine in the brain cells. This evidence in flies is important to study and understand the human brain. In both the cases, storing and erasing, an identical messenger molecule, cyclic AMP is involved, leading to a cascade of activity inside the cell, building or breaking down memory storage. In a new study, researchers from The Scripps Research Institute have detailed the complex biochemical mechanisms about how brain stores scent-associated memories and erase unnecessary memories. The study findings were published in the journal Cell Reports.
The TSRI research team found on G protein (signaling protein) called G alpha S that latched on to dDA1 (neural dopamine receptor) associated with memory formation. Also found another G protein called G alpha Q linked to nearby dopamine receptor, Damb which is associated with the machinery of forgetting. To find whether the two different G proteins can control the fly brain’s memory, they silenced the genes involved in the production of G alpha Q. The flies with silenced genes were exposed to odors and observed how well they remembered to turn away in presence of the scent. They said when G alpha Q is removed flies did not forget and remembered better. This study may help in understanding the process of memory loss, aging and open new doors for treating neurodegenerative disorders.
Study leader Ron Davis said, “The olfactory systems of flies and humans are actually quite similar in terms of neuron types and their connections”, and further asked “If you have too much memory that is old and unnecessary, why keep them around? Why shouldn’t you have a system for removing those for optimal function of the brain?”
More Information: Sophie Himmelreich et al, “Dopamine Receptor DAMB Signals via Gq to Mediate Forgetting in Drosophila”, Cell Reports (2017). DOI: http://dx.doi.org/10.1016/j.celrep.2017.10.108