The following paper will provide a summary of the video, The Mystery of Memory, Documentary, which was part of the AstraZeneca Nobel Medicine initiative. Within the summary, the neurobiology behind memories will be examined, with special focus on learning, remembering, and the memory-emotion connection.
Camillo Golgi accidently discovered a new way of staining neurons, so that their structure could be seen. He hypothesized that neurons are physically connected like a fishnet. At the same time; however, another scientist named Santiago Ramon y Cahal was also interested in nerve cells, and after some experimentation, he improved upon Golgi’s method of staining nerve cells and came to the opposite conclusion. Unlike Golgi, Cahal believed that nerve cells were not continuous, but that they had distinct spaces between them. He later published a paper on his Nerve Theory, but he and Golgi together were awarded the Nobel Prize jointly. Cahal’s theory was later proven right and today forms the foundation for modern neuroscience. The communication between nerve cells takes place at the synapse, which is where (and how) memories are formed.
Memory formation and learning has been the lifework of Nobel Prize winner and renowned neurobiologist, Dr. Eric Kandel. Dr. Kandel began his work on the giant marine snail, Aplysia, to see how it learns and later remembers how to withdraw its gill when it touches something. This was the first direct evidence that learning involves alterations in how nerve cells communicate with one another. Dr. Kandel noticed that when the snail remembers something, a sequence of molecular changes takes a place that strengthens the chemical connection between neuron. This discovery formed the basis of what we know today about how memories are found.
The neurobiology of remembering and recall are specialties of Dr. Fried. He and his team do work with patients, where electrodes are placed into patients’ brains to see how neurons fire in response to learning and remembering. One interesting finding is that the same neurons that they observe firing when someone is learning something (e.g., watching a video), are the same neurons that fire when the person is asked to recall or remember something (e.g., what they saw in the video). This shows that certain neurons are sensitive to particular information and that where the memories are formed is also where they can be accessed. Finally, scientists have also discovered that emotion really helps to sculpt and strengthen memory (e.g., stress hormones). Emotions strengthen the communication between neurons in the amygdala. which can help explain disorders such as PTSD.