Distribution and pharmacological characterization of primate NK-2 tachykinin receptor in the central nervous system of the rhesus monkey.

Tachykinin NK-2 receptor, a cognate receptor for neurokinin A, expressed in the brain has been suggested as a new target for the treatment of psychiatric disorders. In rodents, treatment with NK-2 receptor agonists causes anxiogenic effects, while NK-2 receptor antagonists show anxiolytic and antidepressant-like effects. However, information about the distribution and functions of NK-2 receptors in the central nervous system (CNS) in primates is still lacking. Here, we examined the distribution and pharmacological profile of NK-2 receptors in the rhesus monkey (Macaca mulatta) to clarify the molecular basis of NK-2-mediated tachykininergic functions in the primate CNS. NK-2 receptors cloned from the rhesus monkey brain showed similar pharmacological properties to those of human NK-2 receptors. Substantial expression levels of NK-2 mRNA were observed in all the brain regions examined, including areas pertinent to the emotional networks such as the prefrontal cortex, cingulate cortex and amygdala. These findings suggest that NK-2 receptors may play important roles in the pathophysiology of psychiatric disorders.