Campus research pushes forward
August 1, 2007
During summer break, you can find students engaged in any number of activities. Many use the time to add another entry to their resume through internships or to relax by taking a vacation. But for professors, the summer is often a time to finish research, receive critical feedback and publish papers. This summer has not been any different.
It is this research that helps advance careers and provide money to the University for further development.
We do not remember days, we remember moments
For the longest time, scientists believed that the creation of new proteins in the brain formed long-term memory. But a team led by Prof. Paul E. Gold has put this notion on its head.
The findings were recently published in the multi-disciplinary journal called Proceedings of the National Academy of Sciences. They argue that protein synthesis or creation might not fully explain the story of long-term memory.
Get The Daily Illini in your inbox!
For quite some time, scientists have used drugs that stop the synthesis of certain proteins in order to understand better how the brain functions. It was learned early on that by targeting certain areas in the brains of rats with these drugs, long-term memories could be altered drastically. Thus, it was suggested that these proteins were the key component in the creation of memories.
But Gold and his team have proposed something different. They discovered that one of drugs commonly used in these sorts of studies has the added effect of changing many of the other chemical reactions occurring in the brain.
When lab mice are exposed to this drug, called anisomycin, researchers noticed aftereffects in the levels of neurotransmitters, the substances that regulate and perform normal functions in the brain. Increases in the level of neurotransmitters were as high as 17,000 percent in some of the experiments.
“Normally you think of a 200 percent increase as a really solid result and 300 percent as outrageously high,” said Gold.
After the initial injection, these levels dropped, eventually below the normal baseline.
As was expected, these rats suffered long-term memory loss.
However, the team redid the experiment. This time, they added other drugs to the mix that would stop the fluctuations in neurotransmitters. Even with anisomycin, long-term memory was improved over the baseline tests.
“If we block anisomycin’s effects on the neurotransmitters, then we block many of its effects on memory,” Gold said.
This breakthrough could have implications in the world of Alzheimer’s research.
Gold said that this new insight should push researchers to re-examine some of their assumptions.
Blurring the line between machine and biology
Lead researcher Jean-Pierre Leburton, the Stillman Professor of Electrical and Computer Engineering at Illinois, and his team have recently designed a new semiconductor that offers advantages over current standards.
Semiconductors, which regulate the flow of electrons, are used in a wide variety of applications, most notably in computers, cellphones and personal audio players.
Their design is built from silicon, the same material used in computer chips. However, theirs has been embedded with impurities that give it the same qualities as a biological membrane. These membranes are currently being used in DNA sequencing and other biological research.
Their model has small openings called nanopores that regulate the flow of charged particles. In unison, it acts like a biological ion channel, which itself is an important part of the nervous system.
The artificial version has the added benefit that it can be changed much easier than the biological version, and thus could be useful in research purposes.
The nanopore has an hourglass shape, with a bottleneck 1 nanometer in diameter. At each end of these nanopores, the openings are around 6 nanometers in diameter. This can be altered by changing the electrical properties.
“Using semiconductor technology to sequence the DNA molecule would save time and money,” Leburton said.
It’s science
A new method devised by biochemistry professor John Gerlt could speed up the complex task of identifying thousands of proteins in the DNA sequence.
Proteins, which comes from the Greek word meaning “of vital importance,” have roles in every function of the body from memory to growth and nutrition.
His team is the first to use a fully computational approach to predict the purpose of a protein.
By looking at the sequence of the protein’s building blocks, the amino acids, Gerlt and his team were able to deduce their function. They did this by comparing it to those whose function and structure was already known.
By first looking at other proteins that had common ancestors and were known structurally, they were able to create a basic three-dimensional model. This model was then subjected to computer experiments to see if they would bind to any of the known target molecules. It is this step which is important in the understanding of molecule functions.
Their predictions have been validated by conventional means.
“This study describes an integrated approach using experimental techniques, computational techniques and X-ray crystallography for predicting the function of a protein of previously unknown function,” Gerlt said.
This method could greatly speed up the overall process as there are currently 2 million protein sequences that are known by their amino acid sequence, but have not been assigned a function.