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CAN SCHIZOPHRENIA BE PREVENTED? Researchers believe that schizophrenia occurs when a type of cells in the brain, called microglia, are overactive. These then cut connections between nerve cells – including those that would normally be retained. Carl Sellgren Majkowitz is now to study in detail whether this can be prevented – and if so, how.
On average, one in a hundred people suffer from schizophrenia, which is a chronic psychiatric illness. Carl Sellgren Majkowitz is a researcher at Karolinska Institutet and a Senior Consultant in Psychiatry; his interest in research in this area grew out of meeting such patients over the past 15 years. “In my research I want to carry out relevant experiments in the lab to map the biological processes behind the illness, so that we can use this to improve clinical treatment,” he says. The objective of the project he is leading is to investigate why schizophrenia arises and whether it is possible to prevent it from occurring. The development of knowledge about schizophrenia at cellular level could be described as a multistage rocket. As early as 1982 the question was raised whether a lack of connections between nerve cells in the brain was behind the illness. Post mortem results indicated that individuals with schizophrenia had fewer connections between the nerve cells in the front part of the brain than individuals without schizophrenia. It then took until 2012 until researchers were able to show in tests on mice that there are specific cells in the brain, microglia, that are responsible for eliminating connections between nerve cells. And in 2019 Carl Sellgren Majkowitz made an important discovery: “Using two-dimensional cell cultures with microglia cells and nerve cells derived from patients’ skin cells, we were able to show that microglia cells from individuals with schizophrenia were more active in eliminating connections between nerve cells,” says Carl Sellgren Majkowitz. As the brain matures, its nerve cells link up. These
connections are called synapses. It is via the s ynapses that the nerve cells send signals to each other. In the late teenage years, however, it is time for the microglia cells to eliminate the connections that are not being used in order to reinforce the more important networks. In the study, which was published in the journal Nature Neuroscience, the researchers also made another discovery – the result of an idea that Carl Sellgren Majkowitz describes as a ‘shot from the hip’. “In another context an antibiotic called mino cycline had an inhibiting effect on these very microglia cells. We asked ourselves whether this effect might affect the risk of getting schizophrenia,” he says.
“Another aim is to find markers that make it possible to identify those at increased risk of developing schizophrenia.” They collected data from the health records of 20,000 young people who had been prescribed minocycline to treat acne in their teenage years. Those who had later been diagnosed with schizophrenia were then followed up. “We saw that the incidence of schizophrenia was significantly lower among those treated with mino cycline when compared with others,” he says. The project The rewiring of the connectome in adolescence as a target for preventing schizophre nia is now on the starting blocks. In this project the
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