Connecting European Neuroscience

Johannes GRÄEFF

FENS-Kavli Scholars 2014-2018

Johannes Gaeff was born and raised in the German-speaking part of Switzerland, in St. Gallen. After high school, he moved across the language boarder to the French-speaking University of Lausanne, where he completed his undergraduate studies. During those, he also spent one year at the University of British Columbia, in Vancouver, Canada, where he started to become interested in neuroscience and psychology. His M.Sc. thesis, conducted with Laurent Keller in 2005, focused on the genetic causes of aging in ants. Intrigued by how genes can influence behavior – and vice versa – Johannes then started a PhD thesis in the lab of Isabelle Mansuy at the Swiss Federal Institute of Technology in Zürich (ETHZ) to specialize on the neuroepigenetic mechanisms that regulate learning and memory.

He obtained his PhD in 2009, and stayed on for a short while as a postdoctoral fellow.

In the fall of 2009, Johannes moved to the Massachusetts Institute of Technology in Cambridge, MA, USA to start his postdoctoral work under the supervision of Li-Huei Tsai. During this time, he could for the first time show that epigenetic mechanisms are causally involved in cognitive decline associated with neurodegeneration, as well as with updating long-term traumatic memories in a mouse model of post-traumatic stress disorder.

Since 2013, Johannes is back in Switzerland, where he is a tenure-track assistant professor at the Brain Mind Institute of the Faculty of Life Sciences, and the Nestle Chair for Neurosciences at the Swiss Federal Institute of Technology in Lausanne (EPFL).

Country of origin: Switzerland
PhD: Swiss Federal Institute of Technology (ETHZ), Switzerland (2009)
Affiliation: UPGRAEFF, Ecole Polytechnique Federale Lausanne (EPFL), Switzerland
Previous affiliations: Massachusetts Institute of Technology (MIT), USA (2009-2013)
  Swiss Federal Institute of Technology (ETHZ), Switzerland (2009)  

Research interests: Our lab is interested in three main questions. How and where are long-term memories stored in the brain? Why are memories lost during neurodegeneration such as in Alzheimer´s Disease? How can traumatic memories from the past be overcome?

To answer these questions, our lab focuses on the field of neuroepigenetics. "Epi-genetic" mechanisms, i.e. modifications to the chromatin that regulate gene expression without changing the DNA sequence, have not only been shown to react to fluctuating environmental contingencies, but also to encode the fate of neurons and other cell types during development. With this Janus-faced property of being at once dynamic and stable, we hypothesize that epigenetic mechanisms might underlie the processes that converge newly learned information into a stable memory. Furthermore, because epigenetic mechanisms are also amenable to pharmacological intervention, they might constitute a novel angle on how to counteract memory loss that occurs during neurodegeneration. Finally, we are also seeking to capitalize on epigenetic mechanisms so as to overwrite remote fearful memories into non-fearful ones.

From our studies, a picture is emerging that defines epigenetic mechanisms, in particular histone acetylation, as a memory aid on the chromatin. Now, we “just” need to figure out, how this molecular mnemonic can best be installed and subsequently read.