Signal substances in the brain are the molecules that cells use to communicate and send nerve signals to each other. The cells contain capsules, so-called vesicles, which are filled with a certain amount of transmitter molecules, so-called signal substances, used by the cells for communication and regulatory functions in the organism.
Our short-term memory starts with a chemical process in the brain where brain cells interact with the aid of neurotransmitters that are secreted from these vesicles. The cellular processes that direct the vesicle to start release have been charted and the 2013 Nobel Prize in Physiology and Medicine was given for this. Exactly how this finishes is, however, not known today, but earlier results from Andrew Ewing’s research show that the amount of signal substance that cells emit varies in different situations providing a mechanism for change in signal or learning. By examining the content of signal substance in individual vesicles and comparing to the amount of signal substance that a cell yields, his research shows that it is possible to see at a very detailed level how much signal substance is released from the cell in different situations.
"This discovery provides a completely different view of what regulates neurotransmitter release and shows this regulation is possible at the level of single release events."
Knowledge of this opens up for further research on the transmission of signal transmission and raises questions about the plasticity of the cell wall and how strong the coupling, synapse, between the nervous cells, which can lead to methods that may counter memory diseases.
"This can give us tools to understand the processes that are affected in diseases, such as Alzheimer's disease, adding a new pharmaceutical target by regulating individual vesicles and how they open."
Andrew Ewing has now received an estimate of 2.5 million euro from the ERC to test how extensive the proposed mechanism is, to develop new methods of analysis of nanometer vesicles, and to use this in a next step to investigate full brain cells of banana flies as a model. In addition, he will investigate the role of changes in the membrane of the cell in the chemical reactions that are essential for a functioning short-term memory.
"I have been blessed with being able to interact with great students, postdocs and collaborators with open minds and super ideas. This is a very exciting and far reaching project where many of the things we are investigating are clearly controversial and parts might not work, but that adds to the excitement and this is the kind of work the ERC funds to push science to the future."
In the long run, Andrew Ewing hopes that his research will provide tools to understand how diseases that damage short-term memory work on a deeper level.
Text: Mats Tiborn