Molecular Biology of Neuronal Geometry: Expression of Neurofilament Genes Influences Axonal Diameter

Abstract

Comparisons of the shapes of particular neurons in organisms with the same genotype demonstrate that although the detailed geometry of the neurons may differ, the basic form of these cells is preserved (Macagno 1980). These observations suggest that the information that determines the basic form of these neurons is heritable, and this raises a fundamental question for molecular neurobiology: How is information that is encoded in the genome expressed into the specific geometries of the many different types of neurons that exist in nervous systems? One of the important keys to the solution of this problem resides within neuronal cytoskeletons, because these structures represent the supporting framework that defines the shape of the nerve cell (Hillman 1980). The geometry of the neuron is an external manifestation of the detailed structure of the cytoskeleton.