Phoenixin and nesfatin-1 - novel neuropeptides in anxiety disorders

Anxiety disorders are the most common mental health conditions and currently constitute a significant social and pharmacological issue. The neurochemical aetiology of anxiety has not been fully explained yet, and it has been the subject of numerous basic research studies. In this context, the recently identified highly multifunctional regulatory neurohormones - phoenixin and nesfatin-1 seem to be of special interest. Phoenixin, a neuropeptide of hypothalamic-pituitary-gonadal axis, has potent anxiolytic properties in the animal model. Newly identified hypothalamic and brainstem neuropeptide nesfatin-1 is considered to play an important role in the mechanisms underlying generation of anxiety symptoms in animals. Clinical studies showing decreased serum levels of nesfatin-1 in patients with generalised anxiety disorder are sparse. On the other hand, elevated nesfatin-1 expression was noted in the brainstem of male suicide victims. The neurophysiological effects of both nesfatin-1 and phoenixin seem to be distinctly sex-related. The aim of this review article is to summarise recent reports regarding the postulated involvement of these neuropeptides in the functioning of neuronal pathways involved in the pathophysiology of anxiety responses.