Scientists have known for a while that our memories are the process are synaptic transmissions in our brain and are stored in neurons, but they have been able to film the actual process for the first time inside of a mouse. This groundbreaking video was made in the lab of Robert Singer of Albert Einstein College of Medicine and the paper describing the process was published in Science.

Our lives are defined by our memories. Everything we do, including driving a car, laughing at jokes, cooking dinner, or calling a friend relies on our prior knowledge of similar events. But how is all of this created and stored in our brains? Memory research is extremely complex, but neuroscientists have been able to work a lot of it out.

Memories are made by messenger RNA (mRNA) that encode β-actin protein. These proteins are responsible for shaping and structuring cells in the neurons. As events unfold, β-actin protein is responsible for reshaping the neurons and creating a path, retracing the synaptic steps. Memory retention is delicate business, and it is possible for even a single molecule to determine whether or not the memory is stored. Any disruptions in the process can result in a lost memory.

Because the process is so delicate, it has been incredibly difficult for researchers to see it happen in real time. First, they tagged the mRNA which codes for β-actin protein with green fluorescent protein. Aside from the tag, there was no genetic modification performed on the mouse. By keeping the process as streamlined as possible, the team prevented possibly contaminating the results.

The researchers then stimulated the hippocampus, which is a small region of the brain that has most of the ability to form and store memories. Following stimulation, the researchers were actually able to witness the synthesis of the β-actin-encoding mRNA in the nucleus of the neuron. The molecules were then tracked out to the dendrites, where communication between neurons takes place.

Singer noted that an increase in stimulation correlated with increase in synaptic activity in the predicted location. The outcome of this research was very much predicted by many previous studies dealing with memory, and it is an astounding step forward to be supported with actual real time video showing the process.