FORGETTING

Neural plasticity of both neurons and glial cells is essential to learning and memory, and also involved in several neurological diseases.

Our team studies these plasticity processes during both memory formation and forgetting.  Indeed, while it has often been considered a deleterious process, disremembering (or forgetting) can also benefit cognitive processes, allowing us to unlearn obsolete information and prevent the emergence of disorders such as post-traumatic stress in which emotional memories must be dealt with.

Our recent work suggests that sleep could play an important role in forgetting by inducing a re-organization of synaptic and glial plasticity and of the cortical networks which subserve this process. Local inhibitory interneurons and astrocytes integrate the activity of cortical networks to modulate sleep but also memory. The diversity of interneurons also modifies their activity during the sleep-wake cycle and thus confers dynamic inhibition to the cortical networks.  In pathological condition, our group  showed that glial plasticity is altered. Astrocyte function, mainly through connexins at the interface between cell interactions, is highly disrupted in a model of neuro-inflammation (Devic's neuromyelitis optica). This alteration of glial plasticity leads to neural dysfunction and demyelination. Ongoing studies suggest that ependymal cells alterations could aslo be involved is this deleterious process.