E-Mail IMAGE: Interneuron, stained green, with positive markings for trkB.DN, stained orange, and parvalbumina, stained blue. These results prove that trkB.DN-expressing inhibitory interneurons were successfully inserted by the viral vector... view more Credit: Nicolas Guyon Researchers used genetic engineering tools to create a virus that can enter specific neurons and insert into the prefrontal cortex a new genetic code that induces the production of modified proteins. In tests with mice, the alteration of these proteins was sufficient to modify brain activity, indicating a potential biomarker for the diagnosis of psychiatric disorders such as schizophrenia and autism. Sometimes referred to as the "executive brain", the prefrontal cortex is the region that governs higher-level cognitive functions and decision making. Studies of tissue from this brain region in patients with schizophrenia have detected alterations in two proteins: BDNF (brain-derived neurotrophic factor) and trkB (tyrosine receptor kinase B).