A New Perspective on Memory Mechanisms

18 September 2024

A paper titled “Spatio-temporal mechanisms of consolidation, recall and reconsolidation in reward-related memory trace” by researchers from the Nencki Institute of Experimental Biology, Polish Academy of Sciences (IBD PAN), and the Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw (ICM UW), has been published in the prestigious journal “Molecular Psychiatry.” The scientists discovered how the brain organizes and consolidates reward-related memories. The results have practical significance for addiction research.

The scientists discovered how the brain organizes and consolidates reward-related memories. Studies on rats showed that during the process of consolidation, the activity of specific groups of neurons becomes more specialized, which serves as a mechanism for memory maturation.

In the experiment, the activation of genes associated with learning was visualized and independently measured in over 2 million neurons across 14 brain structures, based on a dataset of nearly 8 TB of microscopic images. Advanced computational methods and machine learning were used in the analysis.

Colored dots indicate the sites of activation of two important memory-related genes. Each neuron has two copies of these genes, one inherited from each parent. Some neurons activate both genes, and the authors focused on these neurons.

The results captured memory maturation, specifically the process of transferring information to increasingly smaller yet specialized populations of neurons. The study also demonstrated that memories associated with the pursuit of pleasure are built through the cooperation of structures responsible for both spatial memory and navigation, as well as emotional states. Knowing the precise location of these memories allows for their modification or even extinction through targeted interventions combining genetic and pharmacological manipulations.

Data collected from the entire population showed that the expression of memory in behavior largely depends on individual traits and variability. In other words, each of us remembers pleasant events slightly differently: for some, emotions are more important, while for others, facts and details take precedence. Highlighting this diversity proves that molecular research enables an effective analysis of memory mechanisms, giving it a qualitative advantage over purely behavioral and pharmacological experiments.

The obtained results have practical significance for addiction research, a condition in which the memory of a pleasant reward and the desire to pursue it become pathological. They also reveal the vast scale of neurodiversity in biological populations.

Authors:

  • Adam Hamed, Nencki Institute of Experimental Biology, Polish Academy of Sciences
  • Miron Bartosz Kursa, Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw
  • Wiktoria Mrozek, Nencki Institute of Experimental Biology, Polish Academy of Sciences
  • Krzysztof Piotr Piwoński, Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw
  • Monika Falińska, Nencki Institute of Experimental Biology, Polish Academy of Sciences
  • Konrad Danielewski, Nencki Institute of Experimental Biology, Polish Academy of Sciences
  • Emilia Rejmak, Nencki Institute of Experimental Biology, Polish Academy of Sciences
  • Urszula Włodkowska, Nencki Institute of Experimental Biology, Polish Academy of Sciences
  • Stepan Kubik, Institute of Physiology, Czech Academy of Sciences
  • Rafał Czajkowski, Nencki Institute of Experimental Biology, Polish Academy of Sciences

Link to the article: https://doi.org/10.1038/s41380-024-02738-8