Scientists at IRB Barcelona discover the mechanism used by neurons to form and maintain nerve extensions
<p>The work was published in <em>Nature Communications</em> and is an interesting discovery for regenerative medicine and neurodegenerative diseases such as Alzheimer’s</p>
Scientists from the Biomedical Research Institute (IRB Barcelona), led by Jens Lüders, lead researcher in the laboratory at the Microtubule Organization, have discovered a new molecular mechanism that is a determining factor in the formation and maintenance of neuronal axons.
The study, published in the journal Nature Communications, also had the collaboration of scientists from the University of Barcelona and was financed by the Spanish Ministry of Economy and Competitiveness and with FEDER funds.
Knowing how the microtubules are formed and how they are organized in a complex and ordered network in the neurons is fundamental to the advancement of neuroscience and can offer clues to axonal regeneration, necessary for the repair of spinal cord injury. The work is also of interest with regard to improving the understanding of neurodegenerative diseases in which the network of microtubules is damaged, such as in Alzheimer’s.
Neurons and axons
The neurons send a constant flow of substances and signals along their axons, which can reach up to a meter in length in humans. Inside the axons is a dense network of microtubules, fine filaments that promote axon growth which, in turn, serve as transport routes.
"The neurons are cells that depend especially on the microtubules for both the internal transport of components and for communicating with each other, but curiously, we don’t understand how they form or organize themselves", says Jens Lüders.
The scientists, when studying neurons in the hippocampus of mice, saw that the differentiated neurons ─which had lost the ability to divide ─ reused a complex molecular mechanism to generate new microtubules inside the axons, which up to then had only be seen during cell division. The scientists propose that in the neurons, the tandem formed by augmin and gamma-tubulin (γTuRC) protein complexes promote the formation of new microtubules alongside existing ones. Thus, the new microtubule "inherits" the same orientation as the old one, favoring the formation of microtubule bundles with a uniform polarity, which is a key characteristic of axons.
Related publication:
- Non-centrosomal nucleation mediated by augmin organizes microtubules in post-mitotic neurons and controls axonal microtubule polarity. Carlos Sánchez-Huertas, Francisco Freixo, Ricardo Viais, Cristina Lacasa, Eduardo Soriano & Jens Lüders. Nature Communications (July 2016) DOI: 10.1038/ncomms12187