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Rahul Kaushik of the German Center for Neurodegenerative Diseases in Magdeburg and his colleagues have created a molecule to reinforce the connections between brain cells called neurons, acting like steel bars in reinforced concrete. Although the approach hasn’t yet been tested in people, injecting this molecule into the brains of mice seems to improve their memories. “It is very clever and has a natural logic to it,” says John Aggleton of Cardiff University, UK. The connections between brain cells, known as synapses, allow signals to jump from one cell to another. Our memories are made of networks of strengthened synapses between millions of brain cells distributed through our heads. To reinforce this, Kaushik’s team has designed a molecule called CPTX. This chemical binds to compounds on the surface of brain cells on either side of a synapse, creating an artificial bridge between the two cells. In Alzheimer’s disease, people gradually lose synapses for decades before the damage is enough to start causing memory loss and confusion. “The idea is you don’t allow the synapses to go away,” says Kaushik. “We don’t let two neurons detach from each other completely.” When the team injected the molecule into mice genetically altered to have Alzheimer’s-like symptoms, they did better in memory tests than the same kind of mice that didn’t receive the chemical. These tests included having to recognise a new object and learning that they would receive electric shocks in a certain location. When the animals’ brains were examined, those that had received the treatment had 30 per cent more synapses than those that hadn’t, Kaushik told the Federation of European Neuroscience Societies meeting in Berlin in 2018. Brain glue holds memories longer BY CLARE WILSON Can we bolt brain cells together to protect our memories from ageing or Alzheimer’s disease? It’s an eccentric idea, but there are signs it could work. The effect tailed off after seven days. But the team is developing gene therapy in the hope that it will make brain cells produce their own supply of the synapse-boosting molecule. “You could have long lasting effects up to years,” says Kaushik. Carol Routledge of charity Alzheimer’s Research UK says that if the technique works, we would also need better tests to detect the onset of dementia several years before symptoms begin. “Lots of people are focussing on early diagnosis. Everyone realises we need to treat earlier than we are doing.” Routledge says the approach might also help people who develop the memory problems common with ageing. “Whether we should be able to slow down cognitive ageing – that’s a whole other question,” she says. A big unknown is whether an artificial synapse strengthened might make it harder to forget things that we normally want to lose, such as day-to-day trivia. Aggleton says people shouldn’t get too optimistic about the approach before it has been tested in people. “There have been lots of studies that seem to show ways of ameliorating changes in. Alzheimer’s disease mouse models,” he says, “but rarely the same positive effects are seen when trials are done with humans. Published with permission. New Scientist issue no. 3191 Headlines 3