title: Lateral septal infusions of the neuropeptide Y Y2 receptor agonist, NPY(13-36) differentially affect different defensive behaviors in male, Long Evans rats.
abstract: The lateral septum has been extensively implicated in regulating anxiety-related defensive behaviors in the rat. Neuropeptide Y (NPY) contributes to anxiety, likely through activity at the NPY Y1 and/or Y2 receptor binding sites. Although the lateral septum contains the highest density of Y2 receptors in brain, the involvement of this receptor in anxiety-related defensive behaviors is not clear. Thus, the purpose of the current study was to characterize lateral septal Y2 receptor contributions to rats' defensive responses to threat and/or potentially threatening environments. We investigated this by infusing the NPY Y2 agonist NPY13-36 into the lateral septum and testing rats across a battery of animal models of anxiety (Experiment 1). To verify the role of Y2 in mediating the observed effects, rats were pre-infused with the potent and highly selective Y2 antagonist BIIE 0246 prior to infusion with NPY13-36 (Experiment 2). Infusions of NPY13-36 into the lateral septum increased rats' open-arm exploration in the elevated plus-maze test (p<0.01) and decreased the proportion of rats' that buried (p<0.05) as well as their latency to initiate burying in the shock-probe burying test (p<0.01). By contrast, NPY13-36 did not affect either anxiety- or appetite-related responses in the novelty-induced suppression of feeding test (all ps>0.3; Experiment 1). Pre-treatment with the Y2 antagonist BIIE 0246 prevented the anxiolytic-like actions of NPY13-36 in the plus-maze but not in the shock-probe test (Experiment 2). Thus, it appears that the anxiolytic-like actions of lateral septal NPY13-36 are mediated by the Y2 receptor in a test-specific manner.
authors.affiliation: Centre for Neuroscience Studies, Queen's University, 62 Arch Street, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Natalie L
authors.initials: NL
authors.lastname: Trent
authors.forename: Janet L
authors.initials: JL
authors.lastname: Menard
mesh_terms: D000378:Agonistic Behavior / Q000187:drug effects*; D000818:Animals; D001007:Anxiety / Q000139:chemically induced / Q000523:psychology; D001066:Appetite / Q000187:drug effects; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D004597:Electroshock; D007267:Injections; D008297:Male; D009478:Neuropeptide Y / Q000008:administration & dosage* / Q000494:pharmacology*; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000494:pharmacology*; D051381:Rats; D020318:Rats, Long-Evans; D017476:Receptors, Neuropeptide Y / Q000819:agonists* / Q000037:antagonists & inhibitors; D020665:Septum of Brain
chemical_list: D001552:Benzazepines; D009478:Neuropeptide Y; D010446:Peptide Fragments; D017476:Receptors, Neuropeptide Y; C062924:neuropeptide Y (13-36); C095889:neuropeptide Y2 receptor; D001120:Arginine; C403256:BIIE 0246