Shanghai local scientists announced yesterday they have discovered a key mechanism in the function of mouse brain neurons, hinting at the possibility of enhancing human memory.

Their findings were published in the May 4 issue of the international scientific journal Neuron.

"Hopefully, our discovery will enlighten the future of brain research as well as the potential of human memory," said lead researcher Duan Shumin from the Shanghai Institute for Biological Sciences.

Over the past three years, Duan and his colleagues have conducted more than 1,000 tests on mice brain tissues to learn why some brain neurons cannot function. The researchers tested the function of a part of the nerve called a synapse that transmits chemical signals to other nerves. The ability of synapses to transmit these signals is at the heart of how nerves function.

For this study, scientists focused on unfunctional or "silent synapses." Research has suggested that large proportions of silent synapses may contribute to poor memory and learning ability.

The key finding featured in yesterday's paper: that some silent synapses are caused by a failure within unfunctional nerves related to release of glutamate. Further, they found that those unfunctional nerves became functional by enhancing glutamate release using electrical stimulation.

The work grew from an accidental discovery three years ago, Duan said, when he found that silent synapses could become functioning synapses with electrical stimulation. But at the time scientists didn't know why. The latest discovery demonstrated the vital role that glutamate plays in this.

Duan's team acknowledged, however, they remain far from finding a way to activate the silent synapses in the human brain, let alone applying the research to make people "smarter."

In an accompanying commentary in the journal, Deniz Atasoy and Ege Kavalali, neuron science professors at the University of Texas Southwestern Medical Center, wrote of Duan's paper, "Their results provide a fresh look at these silent synapses and their switching to active ones."

(Shanghai Daily May 10, 2006)