Neurotubule
Neurotubules are microtubules found in neurons in nervous tissues. Along with neurofilaments and microfilaments, they form the cytoskeleton of neurons. Neurotubules are undivided hollow cylinders that are made up of tubulin protein polymers and arrays parallel to the plasma membrane in neurons. Neurotubules have an outer diameter of about 23 nm and an inner diameter, also known as the central core, of about 12 nm. The wall of the neurotubules is about 5 nm in width. There is a non-opaque clear zone surrounding the neurotubule and it is about 40 nm in diameter. Like microtubules, neurotubules are greatly dynamic and the length of them can be adjusted by polymerization and depolymerization of tubulin. Despite having similar mechanical properties, neurotubules are distinct from microtubules found in other cell types with regards to their function and intracellular arrangement. Most neurotubules are not anchored in the microtubule organizing center (MTOC) like conventional microtubules do. Instead, they are released for transport into dendrites and axons after their nucleation in the centrosome. Therefore, both ends of the neurotubules terminates in the cytoplasm instead. Neurotubules are crucial in various cellular processes in neurons. Together with neurofilaments, they help to maintain the shape of a neuron and