Of Mice and Memory

Duke researchers have uncovered clues to memory and learning by exploring the function of a single gene, WRP, that governs how neurons form new connections. Their findings may also provide insights into a form of human mental retardation.

The scientists studied how WRP functions in brain neurons and then demonstrated how acutely memory and learning are affected when WRP is missing in mice.

In one experiment, the researchers tested normal mice and mice without WRP to see whether they would be able to recognize toys they were familiar with and how they would treat toys that they had never seen before. A mouse with the gene typically spent less time investigating a toy it had seen before, but mice without the gene spent the same amount of time with each toy, suggesting they didn’t remember the toy they had seen the day before.

The group, headed by Scott Soderling, assistant professor of cell biology, also 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. Neurons without WRP, on the other hand, ultimately were defective in making filopodia, which meant that they could not make the correct number of connections, or synapses.