Brain cell proteins are important for long-term memory. A research group at the University of Fribourg has demonstrated the mode of action of a certain protein in fruit flies. These achievements could one day prove invaluable in the treatment of depression, mental disorders and addictions.

The research team, led by biology professor Simon Sprecher, analyzed the extent to which flies could remember a certain smell after a few days. This smell was associated with a reward in the form of sugar. The protein, called CrebB, plays a key role in memory formation, but its precise mode of action was not known until now.

 By applying a relatively recent genetic engineering method (the CRISPR "genetic scissors"), researchers have succeeded in suppressing the CrebB protein in some regions of the brain invoved in long-term memory. They used fruit flies – Drosophila – for their experiments. Drosophila are particularly suitable for exploring these brain mechanisms, as their molecular biology and brain genetics are 99% identical to those of humans.

At first, the flies learned that a certain smell was associated with a reward of sugar. The researchers then tested under what conditions the flies still remembered the association one day later. The tests revealed that the CrebB protein had to be present in two of the three brain lobes and in some outgoing nerve cells for long-term memory to develop.

Useful for the study of dependencies and depressions

In humans, CrebB deficiency has been associated with certain mental disorders, addictive behaviours and depression. Therefore, the findings of the Fribourg researchers could lead to a better understanding of these causal links.

The results have just been published in eLife, an online research magazine on biomedicine and life sciences.