Why does schizophrenia develop later in life

Schiziphrenia: Basel researchers cure schizophrenic mice

Basel researchers cure schizophrenic mice: a method against delusion

Schizophrenia has so far been incurable: But Basel researchers have now been able to completely cure schizophrenia mice. Does the method also work in humans?

Schizophrenia is a serious mental illness. Around every hundredth person is affected. The patients suffer from delusions and hallucinations, from disorganized thinking and have impaired motor skills. They live with false beliefs, have problems with social relationships, and they are emotionally jaded. It is noticeable that the symptoms appear for the first time at the transition between late adolescence and young adulthood. Usually between 18 and 25 years of age for men and between 25 and 35 years of age for women.

The causes of schizophrenia are complex. On the one hand, environmental factors contribute. These can be birth problems, stress, and psychosocial factors. Another factor can be cannabis use in adolescence. Hereditary factors are also involved. The genetic component of this mental illness is around 50 percent. The genetic factors are mostly mutations in a large number of genes, each of which makes a small contribution to the disease.

Deficits in network synchronization

So the disease has complex genetic components. In order to investigate the causes of this disease, the researchers are therefore concentrating on simpler “genetic models”. These can be humans or animals with well-defined mutations that are at high risk of developing. People have a greatly increased risk of developing schizophrenia if they have 22Q11DS syndrome. This syndrome is caused by a chromosome mutation in a segment of chromosome 22. People with this syndrome are 20 to 30 times more likely to develop schizophrenia.

"The procedure could prevent the outbreak."

That is why researchers at the Friedrich Miescher Institute working with Pico Caroni have developed mice with such a chromosome mutation in order to use them as a schizophrenia model in laboratory research. The researchers demonstrated that, as in humans, schizophrenia first appeared in mice between late adolescence and young adulthood. And the mice also showed profound malfunctions in the brain in a certain type of neurons, the parvalbumin neurons (PV neurons). Because of their rapid signal activity, these play an important role in network synchronization in the brain. In schizophrenics, malfunctions in the brain lead to deficits in this network synchronization.

These deficits could be temporarily suppressed in the laboratory test in the mice with antipsychotics. The researchers also found that these PV neurons were already present in the hippocampus of adolescent schizophrenia mice, although these PV neurons did not spread to the brain until adulthood.

Complete and long lasting healing

Caroni examined whether the malfunctions of the hippocampus in the critical phase for schizophrenics after adolescence impaired correct brain maturation in schizophrenic mice. And whether they can prevent the onset of schizophrenia by suppressing network malfunctions during the most critical time window. Long enough to enable the transition to normal adult brain function despite the hereditary burden. The researchers working with Caroni succeeded in doing this. They showed that repeated treatments for six to ten days with common antipsychotics or with specific genetic activators resulted in complete healing. Namely from network malfunctions as well as from cognitive deficits of the schizophrenia mice. For this, the drugs or activators had to be used when schizophrenia first appeared at the transition between late adolescence and adulthood.

"The study shows that it is possible to prevent the progression of schizophrenia through treatment in the critical time window," says Caroni, Professor of Neurobiology at the University of Basel. But how safely is the mouse model transferable to humans? "Nobody can say that." But the mouse model can be reproduced with high accuracy on patients with the 22Q11DS syndrome. “Nevertheless, you still have to test this process before you can predict its possible success. If successful, our procedure could prevent the onset of schizophrenia in high-risk patients, ”says Caroni.