Special issue on "Cytoskeletal proteins in health and neurodegenerative disease: Concepts and methods".

Since 2016, when we compiled a very well-received special issue on "Cytoskeletal Proteins in Health and Neurodegenerative Disease" for Brain Research Bulletin, the field has rapidly evolved, to a large part thanks to the development and maturation of new methods including super-resolution microscopy. Being asked to create a sequel, we therefore decided to keep the main topic, but focus on emerging concepts and novel methods. As before, we compiled nine articles on the role of the neuronal cytoskeleton in both physiological and pathological conditions. Seven of the contributions present current concepts and discuss how cytoskeletal components develop and are maintained throughout a neuron's long lifespan, and also, how they may contribute to physiology and neurodegenerative diseases. Two contributions focus on novel methodological developments and how these techniques can be used to analyze the structure and function of the neuronal cytoskeleton in new ways. The compilation of the articles makes it clear that future approaches must consider the functional relationships between the individual filament systems and the influence different signal transduction mechanisms have on the cytoskeleton and vice versa, in order to adequately explore the causes and consequences of the role of cytoskeletal proteins in health and disease. We hope that this compilation will help in the design of appropriate experiments, aided by new methods, to test critical hypotheses in the field.