Dec. 21/22 – BMI-Agalma-Synapsy joint symposium
Memory Consolidation, Reconsolidation and Extinction
Professors Magistretti, Lüthi and Gräff (all three Synapsy members) offered stimulating talks:
Prof. Pierre Magistretti presented a 35 year-retrospective, as well as the latest data from his lab. He revived the importance of the energy metabolite lactate, revealing how little by little its role in memory formation is becoming established. He carried on to show impressive 3D-electron microscopy data performed at KAUST University, highlighting granules of glycogen in astrocytic processes in the vicinity of the synapses. He, then, concluded with new data demonstrating that modulation of plasticity by lactate also occurs in the lateral amygdala where it impairs the acquisition of a cocaine-induced conditioned place preference, suggesting for the first time, a role for lactate in memory formation.
Prof. Johannes Gräff presented recent insights into remote fear memory attenuation. Traumatic memories are extremely persistent and the exposure therapy-based approach is the most successful behavioral treatment to date in humans. The few published studies using animal models failed to show reduction in remote fear memories with this approach. In his hands, a combination of exposure therapy and pharmacological treatment affecting epigenetic regulation of gene expression resulted in persistent fear reduction at the behavioral level. He presented very exciting results in transgenic mice on the cellular and molecular mechanisms that allow visualization of remote fear memory traces.
Prof. Andreas Lüthi presented brand new data from his lab about the neuronal substrates of fear conditioning. He first explained that the Hebbian plasticity model is not really applicable in the amygdala, the area of the brain regulating fear memories because models based on a single neuron or even a single synapse cannot explain fear conditioning. He then switched to his results on defensive behavior and explained that animals have several defensive behaviors ranging from freezing to fighting. He concluded that two populations of glutamatergic cells therefore exist in the PAG; one induces freezing and the other fighting defensive-behavior.
About 100 persons were present.