Scientists in the US have found a relationship between scent and dopamine activation in the brain cells, associated with memories. The dopamine causes the production of a molecule called cyclic AMP, which leads to either the building or breaking down of memory storage. The study’s leader, Ron Davis, PhD, co-chair of TSRI’s Neuroscience Department, was unable however to establish what caused the cells to either destroy or create the brain’s memories. Speaking in the report, published in the journal Cell Reports, he said, “So how do the cells know when they are getting a forgetting signal verses an acquisition signal? That was the huge, perplexing question.”
Protein and memory
The study was carried out on fruit flies due to the fact that their sense of smell or olfactory system works in a similar way to that of humans. One of the theories behind the body’s propensity to create or forget memories is the type of proteins in neurons. Scientists found one protein called G alpha S, which latched on to neural dopamine receptor that’s linked with memory. They also found a protein called G alpha Q, which had the opposite effect and latched on to a neural dopamine receptor that is linked with memory loss or the machinery of forgetting.
The researchers applied this discovery to fruit flies and hypothesised that if they silenced the G alpha Q protein, it would also remove their ability to forget. The flies were then subjected to unpleasant odours and sent through a maze. The scientists discovered that the flies who had the G alpha Q protein silenced were indeed less likely to forget than the equivalent flies with active G alpha Q nutrients.
The progress in understanding the brain’s functionality when it comes to remembering and forgetting memories could eventually be applied to treating people with memory loss or understanding the nature of memory as we age. Davis believes that the process may be related to the brain’s need to clear out unnecessary memories in order for it to function more effectively and efficiently. “Why shouldn’t you have a system for removing those for optimal function of the brain?,” he said.
Despite their findings, the researchers were keen to emphasise that they are still at a very early stage in their understanding of the intricate biochemical processes that dictate the creation and or forgetting of memories. “We need to figure out what is downstream — walk down the pathway to find the complete signalling system for forgetting,” said Davis.
