Increased tachykinin NK1 receptor immunoreactivity in the prefrontal cortex in schizophrenia

Background: Changes in levels of substance P and substance P-binding sites have been implicated in schizophrenia . However, no studies have used recep tor-specific antibodies to directly investigate the substance P (neurokinin 1) receptor in schizophrenia. Methods: We used an antibody directed against the human neurokinin-1 recept or to compare the distribution of neurokinin-1 receptors in the prefrontal cortices from six subjects with schizophrenia and six control subjects, mat ched for age, gender, and postmortem interval. Results: In control tissue, dots of neurokinin-1 receptor immunoreactivity were observed in layer I to upper/mid layer III only. In contrast, dots of neurokinin-1 receptor immunoreactivity were observed in all layers of the p refrontal cortex in subjects with schizophrenia, and the density of dots wa s significantly greater than in control subjects. Conclusions: This is the first report of increased neurokinin-1 receptor im munoreactivity in the prefrontal cortex in subjects with schizophrenia. The se changes may have implications for understanding the pathophysiology of t he prefrontal cortex in schizophrenia and for the treatment of this disorde r.