This is an assignment I had in a class in the fall of 2018 in a neuro department! The directive was to provide a lay summary of a scientific article that would be read by several anonymous people (professors and non-scientists!). I’m so happy that I took so many of these writing assignments sincerely, irrespective of potential improvements I think I would make in 2024( 5ish years later).
I found it and honestly thought it was kind of neat and shared it with a few neuro focused friends who all seemed to find it interesting!
Since I received Quite encouraging sentiments that persuaded me to share this piece. Note
Please read this as what it is: a HOMEWORK ASSIGNMENT from my first ever neuro class ever so please take all claims under this context, none of these claims should be taken as approved scientifically by original authors as this was a literal homework piece and as such the portrayal of data and perspective are based solely on an attempt to demonstrate what I took from the article and tried to synthesize for a general audience, this post is meant to demonstrate a method or style of summarization of science, not science itself.
Lay summary of
Isaac Cervantes-Sandoval, Molee Chakraborty, Courtney MacMullen, Ronald L. Davis. Scribble Scaffolds a Signalosome for Active Forgetting. Neuron, 2016; DOI: 10.1016/j.neuron.2016.05.010 (1)
Forgetting to remember
Fall 2018 lay summary course assignment
Brian Eno, an innovative musician, said, “I’m always trying to do something new; I make a point of constantly trying to forget and get things out of my mind.” To value forgetfulness seems counterintuitive. We’ve all had frustrating experiences where we forget someone’s name or are unable to find our keys. Yet, recent research demonstrates that forgetting plays a vital role in learning, decision making, and mental health.
To those of us who’ve experienced the irritation and embarrassment of forgetting a birthday or blanking on account passwords, this notion is outright puzzling. How is it possible that forgetting is beneficial to memory and learning? Consider proteins associated with memory as librarians
and your memory as a library, with each book representing a different experience. Over the years, the library collects millions of books, some of which are read more than others, but all of which require space. Suppose a friend asks to borrow Shakespeare’s Hamlet for a class. Since you have millions of books, your library is massive. The librarians must walk down endless aisles looking through each shelf to find it. Even though the library contains Hamlet, it could take
so long to find that your friend’s class may have already finished. Moreover, at some point your library will fill up leaving no room for new books. How could you make this a functional library? One idea is to remove the books which have not been requested in years. Organizing shelvesby storing the most requested books closer the librarians’ desk increases retrieval efficiency and sorts the least used to the furthest shelves, making them easier to locate and discard.
This is the concept underlying how forgetting memories both makes room for storing new memories and for effectively retrieving important ones. In a 2016 study published in Neuron(1), researchers in Dr. Ron Davis’ group at The Scripps Research Institute explored the biological mechanisms of forgetting using Drosophila, commonly known as the fruit fly.
Flies are an excellent model for studying human memory because they are easy to work with given their quick development and short lifespan. They also have similar brain circuitry and genes related to memory to humans. Flies have a relatively simple genetic architecture, making it easier to study genes involved in behavior through DNA modification. DNA provides instructions to make proteins the same way a recipe provides instructions for making cookies.
By removing ingredients one at a time, it’s possible to determine the ingredients important for the cookie’s taste and consistency. Likewise, editing DNA is a useful tool for deducing which genes are important for a given trait. In this study, researchers investigate the role of the gene Scribble in the process of forgetting. In both humans and flies, memory of smell is key for survival. Smells can indicate if food is safe to eat based on previous experiences.
Memory of smell is unique among the senses because the region of the brain involved with odor perception communicates directly with areas important for memory and emotion. A rotten odor evokes feelings of illness that causes avoidance of harmful substances.
In this study, researchers exposed flies to an odor while simultaneously shocking the flies with electricity. During this “learning session,” normal flies learn that the odor is associated with pain. When exposed to the odor again during a “testing session”, flies that remember the shock avoid the odor while those who have forgotten do not. The authors investigated genes involved in forgetting by deleting thousands of different genes and performing this odor memory experiment.
Normally flies forget odor associated shock a few hours after the learning session. When researchers deleted a gene called Scribble, flies avoided the shock associated odor during testing sessions 24 hours after the learning session, long after the normal flies have forgotten. This indicates that Scribble is required to forget. While retaining memories to avoid future pain seems great, researchers sought to understand if memory retention interferes with memory formation.
To investigate this, they again exposed flies to an odor and shock. After enough time passed for normal flies to forget, they exposed flies to a new odor along with shock. In the following testing session, normal flies ran away from the new odor source while Scribbleless flies did not. Researchers hypothesize that Scribbleless flies’ retention of old memories inhibits new memory formation. Like a library with completely packed shelves, there is no space for new material unless books are removed.
After demonstrating that Scribble is involved with forgetting, researches then explored how the process actually works. The Scribble gene encodes a scaffolding protein that provides a framework supporting other proteins. Using the library analogy, Scribble can be compared to a rolling ladder that other proteins use to carry out librarian duties. The authors found that Scribble binds to Rac, another protein essential for forgetting memories.
Rac accomplishes this by remodelling cellular structure. When a neuron receives a signal to forget, Rac uses the Scribble “ladder” to reach books and discard them. Scribble provides a structure that allows Rac to erase
memories creating space for new ones. This research provides new insights into the mechanisms underlying the process of forgetting.
Dr. Ron Davis elaborated on the significance of this study’s findings in an interview with Science Daily,“Understanding the process of forgetting could have an enormous impact on how we treat a whole range of diseases. Certain memories are intrusive and, with sufficient knowledge of how the brain forgets, we should be able to remove selective memories.” (2). This study provides foundation for future research on the process of forgetting and its effect on learning and memory.
References
1. Isaac Cervantes-Sandoval, Molee Chakraborty, Courtney MacMullen, Ronald L. Davis. Scribble Scaffolds a Signalosome for Active Forgetting. Neuron, 2016; DOI: 10.1016/j.neuron.2016.05.010
2. Scripps Research Institute. "Scientists discover new protein crucial to normal forgetting.” ScienceDaily. ScienceDaily, 2 June 2016.www.sciencedaily.com/releases/2016/06/160602132422.html