Gene mutation may affect how schizophrenia patients see reality

A new study from the Massachusetts Institute of Technology suggests that a specific gene mutation prevents patients with schizophrenia from updating their understanding of reality.

Researchers found that the GRIN2A gene mutation prevents people from making decisions and updating their beliefs, thus showing new ways to understand cognitive symptoms and develop treatments.

Schizophrenia is known to have a strong genetic link, affecting about 1% of the population. The risk for this disorder increases significantly among close relatives. Scientists have identified over 100 gene variants linked to the disorder, but many remain poorly understood.

The researchers in this study examined the Grin2a gene, which functions as a brain signalling component. The researchers used multiple genetic samples to demonstrate that mutations in this gene increase schizophrenia risk.

How does gene mutation affect the brain?

The Institute of Technology, Massachusetts, appoints Guoping Feng as a professor in Brain and Cognitive Sciences because he studied the mutation which disrupts essential brain circuits that handle new information processing tasks.

The brain experiences difficulty when it needs to change existing beliefs through new information input from outside sources.

Feng described the circuit as a system which enables us to update our understanding of reality. When the system fails to work correctly, people start to depend on their existing beliefs, which leads them to lose touch with actual events.

The researchers conducted experiments on mice with the mutation to investigate how this mutation affected their behaviour. The animals displayed decision-making abilities which were both slower and less effective when compared to the standard performance of normal mice. The participants kept switching between different choices instead of making a decision about the best choice to make when conditions became different.

The research demonstrated that schizophrenia patients show cognitive difficulties which affect their ability to understand new information.

The study identified the mediodorsal thalamus, a brain region linked to the prefrontal cortex, as central to this issue. The researchers achieved behavioural improvements in mice through the activation of this circuit by light-based techniques.

The research results indicate that schizophrenia cognitive symptoms can be treated through pathway-based treatment methods. The mutation affects a small number of patients, yet scientists believe that the same brain circuit contributes to the disorder's development in most cases.