October 16, 2013. Psychosis reflects disruptions in a complex, and only partly understood, set of brain circuits. One thing is well established, however—psychosis can be controlled with drugs that block the chemical messenger dopamine from interacting with one of its receptors, the D2 type. However, even when antipsychotic drugs completely quell psychosis, problems with thinking and motivation remain in people with schizophrenia. A new study published October 13 in Nature Neuroscience suggests a possible explanation—that these D2 receptors were overactive during childhood or early adolescence and reworked the usual brain-wiring diagram.
Zheng Li at the National Institute of Mental Health in Bethesda, Maryland, and colleagues found that D2 dopamine receptors in mice sculpt the shape of brain cells during this middle period of brain development, and that when they are overactive, they leave the cells with fewer places to receive messages from other cells. Consistent with this, and possibly relevant to schizophrenia, the researchers found that overactive D2 receptors during mouse "early adolescence" led to disrupted wiring and weakened memory in adulthood. (For more details, see SRF related news story.)—Michele Solis.