However, this presumption turned out to be false, as scientists at the Max Planck Institute of Neurobiology have now shown. They are the first to successfully observe both the receiver side and the transmitter terminal of a synapse over an extended period of time. This involved tagging a number of nerve cells with a red fluorescent dye and labelling the connected cells in green. Using a high-resolution two-photon microscope, changes on both sides could be observed in time-lapse sequences. It soon became clear that the transmitter unit of a synapse played a considerably more active role in the assembly and disintegration of the synapse than hitherto assumed. Once the flow of information to be passed on by a cell is reduced, many of the meanwhile superfluous transmitter stations are broken down. Furthermore, since this novel experimental approach enabled them to watch the contacts between boutons and spines breaking down directly under the microscope, the scientists were able to verify that the reduction in the number of spines does, in fact, result in the loss of synapses.
The brain's reorganization is unexpectedly complex
"What is particularly exciting is that, all in all, the number of transmitter terminals remains constant", project leader Valentin Ngerl explains. While the number of synapses is reduced when the flow of information weakens, new transmitter terminals emerge elsewhere in a seemingly balanced fashio
|Contact: Dr. Valentin Naegerl|