Le cerveau, une machine vivante

Following on from the first dossier on the human brain, devoted essentially to what the cognitive sciences and neurosciences teach us about our lifelong learning capacities (Futuribles 428, January-February 2019), we are publishing a second dossier on the plasticity of the brain, its ability to modify its operation over the course of its life as a function of experience. Since this second dossier is more concerned with the morphology and operation of the brain, it relates more to the life sciences and is, for obvious reasons, introduced by Jean-Pierre Henry who has coordinated all the contributions. His article first explains how the brain is formed (in utero) from the sixth week after conception, then how it is shaped throughout existence and how it is permanently regenerating in the hippocampus. Henry then explains how the brain’s capacities develop — particularly those required for memory. In the third part of his article, Jean-Pierre Henry sets out the pathologies the brain may suffer (particularly cerebrovascular accidents) and the progress made in their treatment. Going beyond this, with reference to the challenges that may confront the brain as it ages (particularly Alzheimer’s, Parkinson’s and ALS, which affect a large number of individuals), he shows how plasticity enables the brain to find solutions in cases of dysfunction, and the advances that may ensue from this in the understanding of these pathologies and the potential therapeutic responses to them.