Researchers make it possible to visualize memories

In the May 13 issue of the journal Neuron, Dr. Ron Davis, a BCM professor of molecular and cellular biology, and colleagues demonstrate that the act of instilling a short-term memory actually excites new synapses.

“We have seen a memory trace for the first time,” said Davis. “A memory trace is anything that changes in the nervous system that represents a memory. In this case, we have seen a change in the activity of synapses.”

To achieve this, Davis and his colleagues put a fruit fly (Drosophila melanogaster) in a tube under a microscope. Then they wafted a particular odor toward the fly using a glass tube. As the fly responded to the new odor, portions of its brain called glomeruli that had been altered to fluoresce under the microscope began to light up. That represented synaptic activity. When the odor was combined with an electric stimulus, a new glomerulus lit up.

“This tells us new synapses are becoming active after we have trained the animal,” said Davis. “Something about training switches these synapses on in response to new information. (A synapse is the junction of two neurons where the transfer of impulse or information takes place, often through release of a chemical called a neurotransmitter.) Others who participated in the research include Dr. Dinghui Yu and Dr. Artem Ponomarev, both BCM investigators.

The work was funded by the National Institute of Neurological Disorders and Stroke, the National Institute on Alcohol Abuse and Alcoholism, the Mathers Charitable Trust, and the R. P. Doherty-Welch Chair in Science, which is held by Davis. http://www.bcm.tmc.edu