Researchers, including a Rutgers professor, have taken a closer look at the brain changes linked to schizophrenia by directly measuring synaptic connections in living people. The team used specialized PET imaging to examine synapses, the tiny junctions that allow brain cells to communicate.
The study, published in Molecular Psychiatry, was led by Avram Holmes of Rutgers and Rajiv Radhakrishnan of Yale University, with first author Sidhant Chopra. In all, the research included 122 people, among them 29 diagnosed with schizophrenia, making it one of the largest synaptic density PET imaging studies done so far.
Compared with healthy participants, people with schizophrenia showed a broad reduction in synaptic connections across several brain areas, including frontal and temporal regions as well as areas involved in memory and emotion. The loss was also greater on the left side of the brain than on the right, according to the researchers.
The team said the synaptic pattern did not line up with the brain volume changes usually seen on standard MRI scans, suggesting the two findings may reflect different biological processes. They also found that the areas with the greatest synaptic loss tended to have higher concentrations of receptors for serotonin, gamma-aminobutyric acid and glutamate.
Using computer simulations based on structural brain connections, the researchers identified a likely starting point for synaptic loss in the left frontal lobe. They said future studies will examine how synaptic loss changes over time and how it responds to treatment.
