Gary Lynch, professor of psychiatry and human behavior at UC Irvine, achieved a century-old dream of neuroscientists—to observe changes in brain cell connections following a period of learning.

Synaptic connections, critical to learning, were observed to change in rats’ brains after they learned to navigate a new, complex environment. A control group of rats were given a drug that blocks changes in the rats’ brain which were critical to learning. Subject rats did not learn to navigate the complex environment, confirming the changes in the synaptic connections where responsible for the development of memory.

Until now, no one has seen a physical change in the brain after learning a task. The observation opens the way for one of the great objectives that researchers, during most of the 20th century, were not able to accomplish—to map the distribution of memory across the brain regions. Lynch’s discovery opens the door to producing the first maps of memory, which will help all neuroscientists.