Scientists gain insight into how brains process memory and sense of orientation

How do our brains process memory and sense of orientation? Scientists are gaining insight by studying rats with implanted genes that prompt neurons to fire on command.

Researchers at the Centre for the Biology of Memory (CBM) at the Norwegian University of Science and Technology (NTNU) in Trondheim are studying how the human brain carries out its tasks related to memory and spatial orientation.

The knowledge being generated at CBM will also apply to areas of the brain other than those involved in these specific functions.

"The brain uses the same building blocks for a variety of functions, so our findings for memory and sense of orientation will likely apply to the rest of the brain as well," says Professor Edvard Moser. He heads CBM together with Professor May-Britt Moser.

Sensitive to light

The researchers are identifying which types of neurons are found in the brain's centres for memory and sense of orientation, and their respective functions. This is essential information since different types of memories are formed and stored in different neurons and neural pathways.

In order to identify the neurons, the researchers use gene technology and other molecular biological methods. CBM is one of the first research groups in the world to implement a new technique for identifying the functions of specific neurons.

"First we insert a gene for light sensitivity into the neurons we want to study," explains Professor Edvard Moser. "Then when we illuminate the neurons by laser, they send out electrical signals. By recording where these signals originate, we can see precisely where in the centres for memory and sense of orientation those neurons are located."

Complex neural networks

Another technique being adopted at CBM is recording signals from many neurons simultaneously. This will provide valuable information for future studies, since brain functions involve complex networks of neurons.

"Now we can more closely examine how these networks interact," says the professor.

CBM's studies are pure basic research, but with a strong user perspective, as they could lead to major advances in the future. Findings from CBM may, for example, enhance knowledge about diseases that affect memory, such as Alzheimer's disease.