How do we remember? Life-long learning and memory research - described by 27-year-old Shi Songhai, now working in San Francisco, the United States - earned this year's Young Scientist Prize, awarded by Science magazine and Amersham Biosciences (formerly Amersham Pharmacia Biotech) in the United States.

Shi received this prestigious award for young researchers on on December 5 at the Centennial Nobel Prize ceremony in Stockholm, Sweden.

He was the grand prize winner among six finalists from Germany, Israel, Japan, Sweden and the United States.

Just as weight-training strengthens muscles, learning opportunities "train" our brains to store and process massive amounts of information, Shi said in his prize-winning essay, published in the 30 November 2001 issue of Science.

This brain-strengthening process, described by scientists as the "long-term potentiation" of connections, may help explain how best to promote memory and learning and, perhaps someday, explain why memory can falter, said Shi, now a Howard Hughes Medical Institute research associate at the University of California in San Francisco.

Shi was a graduate student from the State University of New York at Stony Brook, working in Roberto Malinow at Cold Spring Harbor Laboratory, when he first began studying brain connections called synapses.

He wanted to know exactly what causes long-lasting changes in transmissions by these connections. In the brain's hippocampus region, such transmission changes help us form new memories.

In his early work, Shi demonstrated that nerve-cell stimulation - similar to the brain stimulation caused by learning - gives a signal to proteins that help the brain make connections.

These proteins, called receptors, quickly relocate when the brain is stimulated and strengthened by learning. Specifically, the unleashed receptors move from the inside of nerve cells into the branch-like arms of other nerve cells.

Shi and his colleagues reported these findings in Science on June 11, 1999. It was considered one of the 10 scientific breakthroughs of that year by the magazine.

But Shi's work didn't stop there.

The relocation of these AMPA type receptors requires the help of a second receptor called NMDA, Shi said.

And he went on to show that AMPA receptors in the brain relocate in response to stimulation.

Next, he wondered whether these same receptors might actually help strengthen the brain's connections and, therefore, memory.

In fact, Shi discovered that AMPA receptors are incorporated directly into brain connections, thereby strengthening them, in response to learning opportunities.

By fusing a green fluorescent protein to the AMPA receptors, he was able to track their movements using microscopic technology. Through such research, Shi said, scientists may eventually be able to answer the mystery of how we remember.

"Shi Songhai's elegant study of receptor dynamics and synaptic plasticity demonstrates the potential of next-generation investigators, whose new ideas and enthusiasm can spark important fundamental discoveries," said Andrew Carr, CEO of Amersham Biosciences.

"Through the Young Scientist Prize, Amersham Biosciences and Science seek to reward such early accomplishments and promote further advances to benefit human welfare."

Said Monica Bradford, managing editor of Science: "Breakthrough thinking by young scientists like Shi Songhai can trigger a chain-reaction of discoveries as other researchers seek to replicate and further investigate the new findings. At Science, we are proud to be collaborating with Amersham Biosciences to support the next generation of researchers."

Shi was born in 1973 in a small village on the eastern coast of China. His parents are farmers, and his childhood was poor but happy.

"I still remember the times my brother and I spent in the little river in front of our home catching fish," he said.

After finishing middle school in his hometown, Shi attended Tsinghua University in Beijing, "a cradle for outstanding scholars and engineers" for nearly a century.

It was during his five years at the campus that he learned mathematics, physics, chemistry and biology, critical steps towards achieving his childhood dream of being a scientist.

He also won a grant from the Howard Hughes Medical Institute at the University of California in San Francisco.

Shi is currently pursuing post-doctoral studies to further understand how our brains develop and function.

American Association for the Advancement of Science, Amersham Biosciences and Cold Spring Harbor Laboratory contributed to this story.

(12/19/2001) (China Daily)