As reported in the study, researchers identified that when a specific metabotropic glutamate receptor called mGluR5 is turned on, it begins a signaling cascade using calcium to hold a memory trace. In this process – called metabotropic glutamate transmission – rapid-fire inputs just a fraction of a second long initiate a cellular memory process inside individual cells that lasts as long as a full minute.
This fast-acting process is much like what happens in the nonpermanent – or RAM – working memory of a computer. “It’s more like random access memory on a computer than memory stored on a disk,” says Don Cooper, Assistant Professor of Psychiatry at the University of Texas Southwestern Medical Center. Conversely, permanent memories are stored when additional proteins cause brain nerve cells to reorganize and their connections strengthened with one another. According to a statement from the University, this process takes minutes, even hours, to turn on and off. As a result, it is too slow to buffer or temporarily hold rapidly incoming information.
The finding may enable scientists to better understand how the human brain is able to store information that changes quickly. It may also lead to greater knowledge about addictions. Specifically, to gain a deeper understanding of how this short-term memory process relates to addiction, the neurochemical dopamine was applied to memory buffer nerve cells. While dopamine allows humans to better focus their attention and make decisions quickly, some drugs of abuse overload the brain with a surge of dopamine. In the study, researchers discovered that an experimental drug that activates a specific type of dopamine receptor was able to focus the nerve cells. As a result, the memory trace was less susceptible to distraction.
“If we can identify and manipulate the molecular components of memory, we can develop drugs that boost the ability to maintain this memory trace to hopefully allow a person to complete tasks without being distracted,” Cooper says. “For the person addicted to drugs, we could strengthen this part of the brain involved with decision-making, allowing them to ignore impulses and weigh negative consequences of their behavior before they abuse drugs.”
News Release: Single brain cell can hold a memory www.lifescience.com January 26, 2009
