New Group of Gatekeeper Cells Regulating Learning and Memory Discovered

A new group of nerve cells acting as gatekeepers and regulate the process of learning and memory, has been detected. These nerve calls carry a receptor for nicotine that explains our ability to remember and sort information.

This discovery that was made by the researchers at the Uppsala University together with Brazilian collaborators explains our ability to remember and sort information. And these details are carried in Nature Neuroscience.

The discovery of the gatekeeper cells, which are part of a memory network together with several other nerve cells in the hippocampus, reveal new fundamental knowledge about learning and memory.

The hippocampus is the part of the brain that is involved in memory forming, organizing and storing. These newly founded gatekeeper nerve also known as OLM-alpha2 cells provide an explanation to how the flow of information is controlled in hippocampus.

"It is known that nicotine improves cognitive processes including learning and memory, but this is the first time that an identified nerve cell population is linked to the effects of nicotine," says Professor Klas Kullander at Uppsala University.

The new study highlights how the local nerve circuits function in the hippocampus.

"We have used a new technology called optogenetics, in which light is used to stimulate selected nerve cells. We were amazed when we discovered that light activation of the gatekeeper cells alters the flow of information in the hippocampus in the same way as nicotine does," explains coauthor Richardson Leao.

They conducted this study on mice and showed that gatekeeper cells connect to the principal cell of the hippocampus. Active gatekeeper cells prioritize local circuit signals arriving to the principal cell, while inactive gatekeeper cells allow inputs from long-distance targets. Nicotine activates the gatekeeper cell, thereby prioritizing the formation of memories using local inputs.

After this the researchers want to check which type of memory and learning may be selected for by the activation of gatekeeper cells. This information will make it possible to stimulate these nerve cells by artificial means.

"Ideally, one would like to access the positive effects of nicotine on the hippocampus's ability to process information, but without creating the strong nicotine dependence that keep smokers addicted to inhaling dangerous tobacco smoke," says Klas Kullander.