Marie Carlén

PhD Karolinska Institutet Medicine Year of admission: 2012

If researchers could detect the brain patterns that indicate the onset of a mental disorder, they might be able to find ways to prevent or treat such diseases in advance. Marie Carlén uses state-of-the-art methods in the early search for neural signs of schizophrenia.

Connecting animal behavior to brain functions is notoriously hard. Marie Carlén, a neuroscientist at the Karolinska Institutet, uses a groundbreaking tool called in vivo optogenetics: Carlén and her team have bred rats with mutations that make their neurons sensitive to light. The team can use light to switch the cells off and on, then watch how the animals behave and how their brains function.

The specific cells that are Carlén’s quarry are called parvalbumin (PV) interneurons. These neurons affect rhythmic signals in the brain called gamma oscillations, which become synchronized during concentration and seem to reinforce memory. In schizophrenia, the brain waves’ synchronization is disrupted. That has led scientists to hypothesize that dysfunctional PV interneurons might underlie this phenomenon.

As a Wallenberg Academy Fellow, Marie Carlén will monitor rats with light-sensitive PV interneurons that they have modified to be overactive. As the rats navigate mazes, the scientists will trigger the PV interneurons and track changes in the animals’ attention, memory and behavior. The researchers hope that knowledge of this fundamental interplay will lay the groundwork for testing drugs to treat mental disorders.


Photo: Magnus Bergström