Science

For us to function as humans our memories are crucial, but we do not want to remember everything in every little detail but instead we need to extract key information enabling us to deal with future events. This processing of memories – highlighting important events, extracting overlapping, salient information and deleting unnecessary data – underlies knowledge extraction and creation of our semantic (i.e. fact) memories.

The Genzel Lab is interested in investigating the neurobiology of semantic memories, how we go from individual experience to knowledge,  and which factors such as previous knowledge (schemas), novelty, plasticity and disease can influence this processing. To achieve this aim we combine different approaches and investigate mice, rats and humans. In rodents we apply a variety of molecular, electrophysiology, and behavioral approaches such as pharmacology, tetrode drives (units, lfp), immediate early gene analysis and viral methods. In humans, we combine functional magnetic resonance imaging with classic polysomnography in the sleep lab. We use these methods to understand physiological sleep and memory mechanisms in healthy controls as well as investigate effects of disease with animal models and human patients suffering from e.g. depression and schizophrenia.

Additionally, the Genzel Lab aims to develop new behavioural tasks to investigate more complex, semantic memories in rodents (Object Space Task, HexMaze) and promotes better handling methods (no tail-pick ups, see Animal Handling).

Current Research Themes:

• The cortical memory system: plasticity and mechanisms

  Most memory research is focussed on episodic memories and the hippocampus. Instead we are interested in how the cortex learns over multiple experiences. We recently provided the first in-vivo confirmation of the proposition developed in-silico that restrictive plasticity in the cortex is needed during later experiences in a familiar environment to avoid catastrophic interference, i.e. when novel experiences overwrite pre-existing memories (Navarro Lobato Elife 2023). However, when systematically tracking the neural representations of different events that contribute to the creation of a semantic memory, we uncovered that the cortex is not always a slow learner. Instead, our results suggest that the cortex may be a fast but adaptive learner.

• The contribution of the hippocampus to optimizing memories

  Since patient HM the hippocampus has been central in memory research. We are investigating if and how the hippocampus contributes to spatial memory and navigation in our multi-trial tasks and interestingly we discovered that the hippocampus is not necessary for but optimizes these functions.

• Hippocampal-Cortical interactions underlie the optimization function of the hippocampus

  Sleep contributed to memory consolidation, likely by facilitating hippocampal-cortical interactions during ripples, spindles and slow oscillations. Over multiple projects we have investigated ripple subtypes and how they contribute to different types of multi-type memories (Aleman PNAS 2022, Navarro Lobato Elife 2023, Samanta iScience 2024, Aleman iScience 2025, Aleman BioRxiv 2025)