Gene study uncovers clues to memory and learning

WASHINGTON - Scientists have explored the function of a single gene that governs how neurons form new connections.

The study has not only uncovered clues to memory and learning, but has also provided insights into a form of mental retardation.

Scientists at the Duke University Medical Centre explored the gene WRP’s functions in the brain cell and then demonstrated in mice how accurately memory and learning are affected when the gene is missing.

“Human genomics studies have opened the floodgates of information that will benefit people with many different diseases,” said Scott Soderling, an assistant professor in the Duke department of cell biology.

“But it is impossible to correct something without knowing what the exact underlying problem is,” he added.

The researchers knew from previous human studies that when WRP is disrupted, there might be a possible link with severe mental retardation.

They conducted experiments using neuronal cells in a lab dish which showed that cells enriched with WRP went on to form many filopodia, finger-like protrusions that neurons use to connect with one another.

Without WRP, neurons ultimately were defective in making filopodia,which meant they could not make the correct number of connections, called synapses.

In studies on mice with and without the WRP gene, the researchers were able to see behaviour differences.

In one experiment, they tested normal and WRP-deleted mice for their behaviour in recognizing a previously unseen toy versus a familiar toy.

A mouse with the gene will typically spend less time investigating a toy it has seen before, but the knockout mice spent the same amount of time each toy, suggesting they don’t remember the toy they saw yesterday.

“There was a striking difference between the groups of mice. The mice without WRP had difficulty learning and didn’t display typical memory ability in several experiments,” said Soderling.

“Because the excitatory synapses that we are studying form their connections right after birth in humans, we think these specific pathways may even provide an opportunity for early intervention after birth,” he said.

“Abnormalities in these types of synapses have been linked to mental retardation, and also to schizophrenia and fetal alcohol syndrome, where there are abnormalities that could later affect learning and memory,” he added.

The study is published in the Journal of Neuroscience. (ANI)