External Seminar Mathieu LETELLIER

The ability of the brain to constantly adapt its organization to ever-changing stimuli is termed ‘plasticity’ and is a prominent feature not only of learning and memory in the adult, but also of neuronal circuit assembly during developmental critical periods. Connections that are the most active become stronger and more stable, while the less active ones weaken and eventually get eliminated. How does activity make specific synapses stronger or weaker and how does it serve synaptic circuit refinement? In both immature and mature circuits, long-term changes in synapse function and organization involves signaling which regulate the traffic of synaptic proteins including cell adhesion molecules, scaffolding proteins and receptors, but also requires the expression of specific genes through transcription and translation dependent mechanisms. During this seminar, I will first present how the activity-dependent local translation of synaptopodin, a protein related to the spine apparatus, allows the input-specific molecular tagging of mature hippocampal synapses. I will then present current work in which we investigate how specific connections get molecularly encoded in the developing olivo-cerebellar system by implementing the patch-seq technique.