Actin, spectrin and associated proteins form a periodic scaffold in neuronal axons and dendrites, with a period below the resolution limit of conventional microscopy. This Membrane-associated Periodic Skeleton (MPS) is present in all neurons examined across animals, suggesting it is a conserved and fundamental component of neuronal extensions. Most studies have been performed in cultured neurons. However, it is known that axons and dendrites do not develop and behave the same in culture compared to their natural environments, where are exposed to particular diffusive and fixed cues in 3D. In this recently-started project, we will first describe the normal abundance, distribution and regularity of the MPS in axons and dendrites of neurons in the nervous system of Drosophila melanogaster. We will also study how the MPS responds to physiological changes in the architecture of the neuronal processes. For this purpose, we selected two groups of neurons with well characterized axonal and dendritic structures, that also suffer dendritic remodeling during development (ppk neurons in larvae) and axonal remodeling on a daily fashion (pdf neurons in adult fly). Image acquisition will be performed by super-resolution approaches (Expansion Microscopy and STED). We expect that in tissue, a given neuronal population will share a characteristic arrangement of their MPS across their distinct subdomains and will be consistently remodeled during physiological changes in neuronal architecture.