Bonn researchers explore the neural processes that help link different aspects of episodic memory.

Bonn, September 10 – Our brains possess an incredible ability to encode and store memories, capturing the essence of our experiences by linking the ‘who/what,’ ‘where,’ and ‘when.’ In a recent study, Prof. Florian Mormann and his research team at the University of Bonn’s Department of Epileptology have provided new insights into the neural mechanisms that support episodic memory formation.

Episodic memory—the ability to recall specific events and experiences—depends on the brain’s capacity to capture and interconnect the details of these events. Although significant progress has been made in understanding memory processes, the precise neuronal mechanisms that enable successful memory encoding are still being uncovered.

This study involved measuring single-neuron activity in the human medial temporal lobe (MTL) during the encoding of item-location associations. The researchers identified two specialized sub-groups of neurons that are instrumental in this process. The first group, known as concept cells, is located in the hippocampus, amygdala, and entorhinal cortex (EC). The second group consists of parahippocampal location-selective neurons.

The study revealed that neurons in both item- and location-selective populations exhibited significantly higher firing rates during successfully encoded trials. These findings lend strong support to the theory of hippocampal indexing, where selective index neurons may function as pointers to neocortical representations, effectively linking the ‘what’ and ‘where’ of episodic memories.

This research offers valuable insights into how distinct populations of neurons contribute to the formation of episodic memories. The discoveries made by Prof. Mormann and his team not only deepen our understanding of memory encoding but also lay the groundwork for future explorations into the neural foundations of memory.

For further details, please refer to the full publication https://www.nature.com/articles/s41467-024-52295-5

Publication: Mackay, S., Reber, T.P., Bausch, M. et al. Concept and location neurons in the human brain provide the ‘what’ and ‘where’ in memory formation. Nat Commun 15, 7926 (2024).

Scientific contact:
Prof. Florian Mormann
Department of Epileptology- Cognitive and Clinical Neurophysiology
Bonn University Hospital
E-Mail:  fmormann@yahoo.de

Written by: Dr Michela Barboni, Ph.D