Super-resolution microscopes have revealed an entirely new type of connection between neurons in the brains of mice and humans.
A team of researchers led by neuroscientist Minhyeok Changfrom Johns Hopkins University, identified small tubular bridges at the branching ends of cultured neurons.
In additional testing in mouse models of Alzheimer’s disease, it was found that these bridges transported calcium and disease-associated molecules directly between cells.
“Similar structures can carry a wide range of materialsfrom small ions (10⁻¹⁰ m) to large mitochondria (10⁻⁶ m)”, write the researchers in presenting the results of the study, which was published at the beginning of the month in the journal Science.
“In cultured neurons, we observed the dynamic formation of these nanotubes and we confirmed that they had a distinct internal structure, differentiating them from other neuronal extensions”, add the study authors
It is well known that the neurons transmit fast messages among themselves through synapses, communicating both electrical and chemical information. However, notes , other types of cells are known to use physical connecting tubes to exchange molecules.
Chang and his team, using advanced imaging and machine learning techniques, have now confirmed that a similar type of tubular bridge also occurs in neurons.
The researchers observed the nanotubes carrying amyloid-beta molecules that had been injected into the brain cells of mice. These molecules are associated with neurodegenerative diseasessuch as Alzheimer’s, in which they tend to clump together in an abnormal way.
When researchers prevented the formation of bridgesthe spread of amyloid-beta between cells also ceasedconfirming that nanotubes function as direct conduits.
“Our computational model supported these findings, predicting that a overactivation in the nanotube network could accelerate the toxic accumulation of amyloid in specific neurons, thus establishing a mechanistic link between changes in nanotubes and progression of Alzheimer’s pathology”, explain the researchers.
We are still in the early stages of this investigation; Since these tubes are such a recent discovery, It is not yet known what they are carrying. naturally nor how often they form or function in the entire human brain.
However, the malfunction of these tubes It may also contribute to other diseases, so researchers are eager to better understand these miniature bridges.
