Where did I park the car? What time is my dentist appointment? Did I lock the doors? Oh no, it's Mom's birthday tomorrow! We are all very familiar with forgetting. It's incredibly frustrating, and sometimes it seems like your brain just isn't working. But it turns out that forgetting is just important as remembering; and it's actively regulated. Forgetting ensures that unnecessary information is removed from the brain, and is critical for its normal functioning.
In a study published last week in the journal Cell, scientists searched through potential genes in the roundworm C. elegans in order to find a likely candidate involved in forgetting. They subsequently discovered a gene that produces a particular protein, called musashi, that was found to be critical for time-dependent memory loss. In a learning task investigating the movement of these animals in response to either attractant or repellant odorants, they found that the genetically modified worms lacking musashi had the same learning abilities as their unmodified counterparts. Then, in a longer experiment, the ability of these animals to retain a particular behaviour over time was tested, and it was discovered that the worms lacking musashi showed a strong increase in memory-retention. In other words, the worms lacking the musashi protein could remember things just as well as the unmodified worms, but they forgot less information.
Neurons are a type of brain cell, and the connections between these cells that facilitates cellular communication are called synapses. These connections strengthen in the process of learning and memory formation, which was found to be assisted by the protein adducin. Musashi, however, was found to disrupt this by inhibiting the production of certain proteins which facilitate the stabilisation of synaptic connections. The study concluded that a delicate balance between these two pathways is required for memory retention, and that an imbalance may result in altered memory function and could possibly contribute to memory-related disorders.
While it is still early days, it is hoped that further study into this field may yield advances in the discovery of therapeutic targets in certain diseases involving memory loss, such as Alzheimer's.