In many cases, a delay occurs between the time you are presented information and the time you respond with an action or decision. Most of us call it a thought, while some scientists call it working memory. University of Wisconsin-Madison researchers believe they now understand on the cellular level how working memory holds a piece of information – or thoughts linger. They found the molecular sensor that controls a little-understood phase of nerve cell communication that keeps a message alive well after it has been delivered.
“The sensor could play a role in keeping a thought ‘on line’ until it is either lost or burned into longer-lasting forms of memory,” says lead author Dr. Edwin Chapman, a Howard Hughes Medical Institute professor at the UW School of Medicine and Public Health.
The study explaining sustained slow nerve cell communication appeared recently in the journal Cell. When one nerve cell sends a signal to another at a synapse, most of the communication takes place instantaneously, with an electrical impulse causing calcium in the sending cell to release a shot of neurotransmitter into the receiving cell. The much-studied action, which makes up the bulk of activity between communicating nerve cells, ends in milliseconds. But a second, slower phase often follows, in which the signal hangs on such that residual levels of calcium continue to drive the release of neurotransmitters over a much longer period-seconds. Overlooked for a long time, this slow phase of nerve cell communication (also called asynchronous) is now clearly in the spotlight following the Wisconsin studies.