Central administration of Y2R agonists have failed to alter anxiety-like behavior in a number of studies (Broqua and et al, 1995, Heilig and et al, 1989, Britton and et al, 1997 and Sorensen and et al, 2004). However, agonism of Y2R in the locus coeruleus and lateral septum produces anxiolytic effects, whereas Y2R are required for NPY-mediated anxiolysis in the hippocampus (Kask et al., 1998a, Kask et al., 1998b, Kask et al., 1998c, Trent and Menard, 2013 and Smialowska and et al, 2007). Y2R agonism in the basolateral amygdala has bidirectional effects on anxiety in the social interaction test, with low agonist doses generating anxiety and high doses decreasing anxiety (Sajdyk et al., 2002). A recent study

indicates that knockout of the Y2R in GABAergic neurons located Imatinib chemical structure in the central nucleus of the amygdala was anxiogenic specifically in female mice (McCall et al., 2013). Contrasting reports indicate that Y2R antagonism in the central nucleus of the amygdala is anxiolytic (Kallupi et al., 2013), and that ablation of Y2R in either the basolateral or central nucleus of

the amygdala SCR7 cost produces an anxiolytic phenotype (Tasan et al., 2010). Global deletion of Y2R reduces anxiety in the elevated plus maze, light–dark, open-field, and marble burying tests (Tasan and et al, 2009, Painsipp et al., 2008, Painsipp and et al, 2008 and Tschenett and et al, 2003), and Y2R deficient mice exhibit reduced neuronal activation upon exposure to an anxiogenic environment (Nguyen et al., 2009). Taken together, this evidence Carnitine dehydrogenase suggests that Y2R may function in a regionally specific and neurochemically selective fashion. The Y4R and Y5R also have putative roles in rodent anxiety-like behavior. Similar to Y2R mutant mice, deletion of the Y4R also reduces anxiety-like behavior in a number of rodent paradigms

(Tasan and et al, 2009 and Painsipp and et al, 2008). Knockout of the Y4R with the Y2R enhances the anxiolytic phenotype observed following deletion of either receptor alone (Tasan et al., 2009). Finally, pharmacological studies indicate that Y5R ligands may have promising anxiolytic properties. A Y5R antagonist blocked the anxiolytic effects of a Y2R agonist in the basolateral amygdala (Sajdyk et al., 2002), while i.c.v. delivery of a Y5R agonist produced anxiolytic effects (Sorensen et al., 2004). Y5R can form heterodimers with Y1R (Gehlert et al., 2007), and these receptor subtypes are colocalized in the basolateral amygdala, hippocampus, and hypothalamus (Wolak and et al, 2003, Longo and et al, 2014, Oberto and et al, 2007 and Fetissov et al., 2004). Y1 and Y5 receptors act synergistically in the regulation of energy homeostasis (Mashiko et al., 2009). Although the combined effects of Y1 and Y5 receptor agonists have not been tested in the context of anxiety thus far, the notion of co-activating these receptors could be valuable in the development of pharmacotherapeutics for enhanced anxiolytic effects.