Role du sommeil pour la consolidation de la mémoire: Implications pour la maladie de Parkinson

 

Soraya Lahlou

Institut et hôpital neurologiques de Montréal

 

Domaine : neurosciences, santé mentale et toxicomanies

Programme Formation de maitrise

Concours 2019-2020

Partenaire:

Parkinson Québec

There are important cognitive changes even in the early stages of Parkinson's disease. The proposed research aims to investigate two possible mechanisms for these observed cognitive changes: 1) whether a reduction in dopamine leads to impaired memory consolidation, and 2) whether altered sleep structure interferes with the normal process of memory consolidation. Fundamental processes that support memory and learning are altered in patients with Parkinson's disease due to deterioration of the basal ganglia and a reduction of dopamine. Dopamine is not only important for the initial phases of learning, but research in animals has shown that dopamine also helps to establish different forms of long-term memory (e.g. motor habits and declarative memory). In particular, dopamine modulates the process of memory consolidation, which is the stabilization of new learning for storage in long-term memory.

Our first study will determine whether the memory consolidation process is reduced in patients with Parkinson's disease and whether this reduction depends on dopaminergic medications. Sleep is also known to be critical for the consolidation of several types of memories, both motor and declarative. This is relevant to Parkinson's disease as up to 90% of patients have sleep disorders, and in many patients, the underlying structure (slow wave sleep, Rapid Eye Movement sleep) is altered. In some cases, these changes may even predict the development of dementia. The mechanism underlying the relationship between sleep disorders and cognition in Parkinson's patients remains unknown. Our second study will determine whether abnormal sleep patterns in Parkinson's patients interfere with the normal process of memory consolidation that occurs during sleep.