14 DAY TRIAL // Experts studying the human brain have for a long time known that neurons communicate with each other through vesicles no more than a couple of hundred nanometers wide. These vessels transport neurotransmitter molecules, which, when they bind to a neuron, release a series of chemicals that are picked up by the next neuron in line and so on. However, a more detailed knowledge of how this occurs is still unknown, and therefore makes the object of a new study, conducted by experts at the University of Copenhagen, AlphaGalileo informs.
“Contact between vesicles and membranes are an essential step in many important biological processes. We can now quantify contact areas formed between vesicles and determine the vesicle size and shape with nano-scale resolution. This helps us characterize the properties of the molecules involved in vesicle-fusion. The new method opens great new prospects for the research of neurological and infectious diseases,” explains Associate Professor Dimitrios Stamou, from the university's Department of Neuroscience and Pharmacology and Nano-Science Center.
Disruptions that occur in the way these vesicles act can lead to the majority of known mental illnesses, including depression. Therefore, understanding how they work is of paramount importance in devising a new course of treatment for these conditions, or even methods to prevent the damage from occurring in the first place. In their new investigation, the Danish researchers are using a viewing method known as Fluorescence Resonance Energy Transfer (FRET) to analyze the intricate connections that exist between neurons in the developed brain.
The team created artificial vesicles similar to those that trigger neuron activity in the lab, and placed fluorescent donor molecules inside them. Membranes similar to neural ones, which contain acceptor fluorescent molecules, were then affixed to a surface. When the two molecules are in close proximity, they emit light, but not before or after. FRET then allows the team to peek at the interactions between the molecules and the membranes, and to discover the size of the vesicles at the nanoscale, all in real time.
“We have lacked a method for measuring the fusion of vesicle and membrane on a nano-scale at the moment the process occurs. Until now it has only been possible to get a still image of the process with high resolution, or live images with low resolution. With the new method we can quantify the changes in vesicle shape live i.e. during fusion, and with nanoscale resolution,” Stamou concludes.