University of London College of Neurologists have used laser beams to “connect” mice ‘neurons, providing a new insight into the hidden memory function, showing how memories justify the brain’s internal GPS system.
The study, published in the journal Mobile:, explains how the researchers used “all-optical” approaches, using twin lasers to simultaneously read and write the activity of “local cells” (a type of neuron) in mice as they moved around in virtual reality.
Significantly, by stimulating local cells, the scientists were able to reactivate (or retrieve) the memory of the place where the mice were being rewarded, which in turn “mentally imaged” the mice, arguing that they seemed to be among the rewarded. place:
This new study is based on the groundbreaking work of Professor John von O’Keefe (UCL Cell Developmental Biology), who was awarded the 2014 Nobel Prize in Detection of Local Cells. These cells are found in a region of the brain called the hippocampus, which is activated only when an animal enters a certain area of the environment.
Local cells are thought to represent a cognitive map of the environment, such as internal GPS, and store location memory. The new UCL study is the first to directly show that cell site activity underlies the brain’s ability to navigate.
The results give a deeper insight into how memories are stored. C UCL scientists believe the findings may eventually help us develop new therapies for conditions such as dementia և Alzheimer’s diseases that affect memory.
The first author, Dr. Nick Robinson (UCL Wolfson Institute for Biomedical Research), said: “These results provide direct causal evidence that mice use information provided through local cell activity to control their behavior. In other words, the local cells really tell the mouse where it is, and the mice “listen” to the cells in their area when making decisions. It gives a new insight into how memories are stored in the brain, as well as new tools for manipulating those memories to influence behavior. ”
He added. “Memory disorders, such as dementia տ Alzheimer’s, are a huge cost to society. “This work may eventually lead to a better understanding of these diseases, as well as new targets for treatment.”
Senior author Professor Michael Hauser (UCL Wolfson Institute for Biomedical Research) said: “This study is game-changing because it shows that we can use optical reading of the activity of certain neurons to write, to manipulate memories, allowing us to better understand, ում potential improvement. how the activity of the neural circuitry helps us make decisions. ”
The experimental study explained:
Researchers at the UCL Wolfson Institute for Biomedical Research have developed a powerful approach that combines two revolutionary technologies that use light to read and write electrical activity in the brain.
First, they developed neurons to express genetically encoded calcium sensors that allow cells to light up when they are active. Second, they expressed photosensitive “optogenetic” proteins in the same neurons, allowing them to activate specific cells with laser light directed by digital holography (the same technology used in laser light show).
By combining these two techniques, the team could “record” and manipulate activity in the same neurons in the brain of a mouse navigating in virtual reality.
UCL scientists have used this approach to perform targeted activation of local cells in the hippocampus of mice navigating a specific area of the virtual world to receive a sugar water reward. They first optically recorded the activity of a large number of cells in the hippocampal area, identifying those that were active in the specially assigned site, which in turn could be the basis for that site. They then used holographic laser beams to activate cells in this particular area elsewhere in the virtual world.
Significantly, the stimulation of local cells was sufficient to restore the memory of the given place by pushing the mouse to look for the gift in a new place. In other words, the stimulation of neurons by light “mentally removes” the animal, causing them to behave as if they were in a rewarded place. This is the first demonstration of how activating local cells allows us to recover memories of our environment and help us navigate.
Reference. Nick T. Robinson, Lucy A.L. Descamps, Lloyd E. Russell, Maurice O. Buchholz, Brendan A. Natbrunn, Christoph Schmidt-Heeber և Michael Hauser, November 6, 2020 Mobile:,
DOI: 10.1016 / j.cell.2020.09.061:
Funding for this study was provided by Wellcome, the Gatsby Charitable Foundation, the European Commission, the European Organization for Molecular Biology, the Medical Research Council and the European Research Council.