Location: Centre Broca
Study of the link between synaptic plasticity and behavioural adaptation
Memory can be defined as the ability to store information within the brain in a way that allows retrieval of such information and promotes behavioural adaptation. At the biological level, memorization is a complex mechanism which demands coordinated brain-wide interactions and is subject to progressive decline upon natural aging. It is a shared idea that understanding the mechanisms regulating formation and storage of memories could help in developing targeted approaches for mnemonic deficiency.
The hippocampus is considered to be main site of recent memory consolidation and the prefrontal cortex has progressively emerged as an important site for remote consolidation, making the communication between these two areas a main centre of interest. During sleep, the lack of additional experience favours memory consolidation and the coordinated reactivation of neuronal assemblies of both the hippocampus and neocortical areas during fast-oscillatory hippocampal events called Sharp Wave-Ripples (SPW-Rs) is now taken has the principal hallmark of memory consolidation. At the molecular level, long-term potentiation (LTP) is the most studied mechanisms for the formation of long-lasting memories.
I studied the interplay between the dorsal hippocampus (dHPC) and two neocortical areas in the context of consolidation of the rule for successful completion of a Delayed Spatial Alternation (DSA) task. We aimed to answer the following questions:
1) Does the medial Prefrontal cortex (mPFC) and the Posterior Parietal cortex (PPC) participate in the engram sustaining acquisition of this rule? Is their participation equal or are they quantitatively or qualitatively differentially solicited?
2) Both areas display signs of hippocampal modulation, in the form of coherent oscillations and coordinated neuronal firing patterns during hippocampal SPW-Rs; how is this modulation modified by consolidation of this rule?
3) Does preventing LTP within the neocortex affect consolidation of this rule?
Keywords: Memory, hippocampus, associative cortices, behaviour, electrophysiology
CA3 hippocampal synaptic plasticity supports ripple physiology during memory consolidation
Manuscript in preparation
Mme Aude PANATIER (DR CNRS) Université de Bordeaux, Bordeaux Présidente
M. Christoph SCHMIDT-HIEBER (PR) Université d’Iéna, Iéna Rapporteur
M. Thierry GALLOPIN (MC) ESPCI-ParisTech, Paris Rapporteur
Mme Audrey HAY (CR CNRS) Université de Lyon 1, Lyon Examinateur
M. cyril DEJEAN (CR INSERM) Université de Bordeaux, Bordeaux Membre invité