“…For instance, clonidine, an a2-AR agonist, is used as an anti-hypertensive agent that acts on cardiovascular regulatory centers in the brainstem (Yamazato et al, 2001). In psychiatry, other a2-AR agonists are used as antidepressants (Davis et al, 2001) including mirtazapine which is an a2-AR, 5 HT2 and 5-HT3 serotoninergic receptors' agonist (Sanders et al, 2011) used to treat social phobia (Mrakotsky et al, 2008) and to improve cognitive functions (Arnsten et al, 1996;Franowicz and Arnsten, 1999;Franowicz et al, 2002). Guanfacine, an a2A-AR selective agonist, has been used to treat patients suffering from attention deficit hyperactivity disorder (ADHD) (Sallee et al, 2009) and other psychiatric disorders (Faraone and Glatt, 2010;Sallee and Eaton, 2010;Taylor and Russo, 2001).…”