Johannes Felsenberg

Neural circuit mechanisms of memory re-evaluation

We investigate how neural processes allow memories to be changed. When actual experience does not accurately match a learned expectation, the underlying memory needs to be re-evaluated to ensure accurate behavior. The adjustment of learned information can be achieved by either adding a new but conflicting memory or update the original memory. To update a persistent memory, it first needs to be destabilized to become rewritable. The changed memory as to be re-stabilized to persist over time. This retrieval induced process is called memory reconsolidation. The Felsenberg group studies the tractable brain of the fruit fly Drosophila to understand fundamental neural operations of memory re-evaluation and reconsolidation.

Flies can learn to seek or avoid odors, previously associated with reward or punishment. Genetic tools in the fly allow us to investigate the neural circuitry involved in olfactory learning and information storage down to single neuron resolution. We combine behavioral assays, thermo- and optogenetic manipulations with in vivo imaging, to gain a mechanistic understanding of memory update systems. We are investigating how new information is integrated into existing memories and how this update changes the neural representation of the memory.
Under certain circumstances, memories seem to be protected from the temporary fragility of reconsolidation. Such limitations, or boundary conditions, of memory re-evaluation allow us to explore the neural underpinnings with greater depth. With our research, we aim to explain how different types of memories can be permanently changed or - under certain circumstances – even erased.



Johannes Felsenberg