title: Hindbrain orexin 1 receptors influence palatable food intake, operant responding for food, and food-conditioned place preference in rats.
abstract: BACKGROUND
  Brain orexin 1 receptors (OX1Rs) are involved in food-motivated behavior. Most research has focused on forebrain OX1R populations, but hindbrain OX1Rs affect feeding. We hypothesized that hindbrain OX1Rs affect the reward value of food.
  
  
  OBJECTIVE
  We examined the effects of hindbrain OX1R stimulation or blockade on motivation for food, palatable high-fat (HF) food intake, and food-conditioned place preference.
  
  
  METHODS
  Rats trained to lever press for sucrose on a progressive ratio (PR) schedule received fourth intracerebroventricular (icv) injections of vehicle, orexin-A (0.1-1 nmol), or the OX1R antagonist SB334867 (10-20 nmol) before operant test sessions. Effects of these treatments on HF food intake during daily 1-h tests were assessed with fourth icv and nucleus of the solitary tract (NTS) injections. We conditioned a place preference by pairing HF food with one side of a two-sided chamber and then examined the effect of 20 nmol fourth icv SB334867 on the expression of that preference.
  
  
  RESULTS
  In ad lib fed rats on the PR schedule, fourth icv orexin-A significantly increased responding and breakpoint relative to the vehicle. In 24-h food-deprived rats, fourth icv SB334867 significantly decreased responding and breakpoint. Orexin-A delivered to the fourth ventricle (0.1 nmol) or NTS (0.01 nmol) increased HF diet intake. Fourth icv SB334867 did not affect HF food intake, but SB334867 delivered either fourth icv (20 nmol) or intra-NTS (5-10 nmol) suppressed chow intake. Expression of HF food-conditioned place preference was inhibited by fourth icv SB334867.
  
  
  CONCLUSIONS
  Hindbrain OX1R activity affects food-motivated operant behavior and may play a role in responding to cues that predict palatable food.
authors: Department of Psychology and Program in Neuroscience, Florida State University, Box 3064301, Tallahassee, FL, 32306-4301, USA.
authors: Kristen
authors: K
authors: Kay
authors: Eric M
authors: EM
authors: Parise
authors: Nicole
authors: N
authors: Lilly
authors: Diana L
authors: DL
authors: Williams
mesh_terms: D000818:Animals; D001583:Benzoxazoles / Q000008:administration & dosage / Q000494:pharmacology; D002755:Choice Behavior / Q000187:drug effects / Q000502:physiology*; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology*; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D057967:Infusions, Intraventricular; D047908:Intracellular Signaling Peptides and Proteins / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D009287:Naphthyridines; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology; D000068796:Orexin Receptor Antagonists; D064446:Orexin Receptors / Q000819:agonists / Q000502:physiology*; D000068797:Orexins; D051381:Rats; D012055:Reinforcement Schedule; D012249:Rhombencephalon / Q000187:drug effects / Q000502:physiology*; D017552:Solitary Nucleus / Q000187:drug effects / Q000502:physiology; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: C420062:1-(2-methylbenzoxazol-6-yl)-3-(1,5)naphthyridin-4-yl urea; D001583:Benzoxazoles; D047908:Intracellular Signaling Peptides and Proteins; D009287:Naphthyridines; D009479:Neuropeptides; D000068796:Orexin Receptor Antagonists; D064446:Orexin Receptors; D000068797:Orexins; D014508:Urea
references: Psychopharmacology (Berl). 2013 Mar;226(1):155-65
references: 23096770
references: Pharmacol Biochem Behav. 2002 Jan-Feb;71(1-2):277-82
references: 11812533
references: J Comp Neurol. 2005 May 2;485(2):127-42
references: 15776447
references: Am J Physiol Regul Integr Comp Physiol. 2009 Nov;297(5):R1238-46
references: 19726710
references: Peptides. 1999;20(9):1099-105
references: 10499428
references: J Comp Neurol. 2001 Jun 18;435(1):6-25
references: 11370008
references: Front Neuroendocrinol. 2010 Jan;31(1):61-78
references: 19836413
references: Endocrinology. 2009 Mar;150(3):1202-16
references: 19008313
references: Pharmacol Biochem Behav. 2001 Jul-Aug;69(3-4):373-82
references: 11509194
references: J Neurosci. 2009 Sep 9;29(36):11215-25
references: 19741128
references: J Neurosci. 1998 Dec 1;18(23):9996-10015
references: 9822755
references: Eur J Neurosci. 2010 Jan;31(2):336-48
references: 20039943
references: Am J Physiol Regul Integr Comp Physiol. 2003 Jun;284(6):R1436-44
references: 12736179
references: Neuroscience. 2012 May 17;210:243-8
references: 22433299
references: Brain Res. 2000 Feb 21;856(1-2):37-47
references: 10677609
references: Science. 1981 Jul 24;213(4506):451-2
references: 6264602
references: Cell. 1998 Mar 6;92(5):1 page following 696
references: 9527442
references: Am J Physiol Regul Integr Comp Physiol. 2011 Dec;301(6):R1692-9
references: 21957165
references: Neuropharmacology. 2013 Oct;73:274-83
references: 23770258
references: Physiol Behav. 2010 Jul 14;100(5):419-28
references: 20338186
references: Behav Neurosci. 2004 Jun;118(3):479-87
references: 15174925
references: Psychopharmacology (Berl). 2008 Jul;199(1):109-17
references: 18470506
references: Biol Psychiatry. 2013 May 1;73(9):811-8
references: 23374642
references: Br J Pharmacol. 2008 May;154(2):406-16
references: 18223663
references: J Pharmacol Exp Ther. 2003 May;305(2):507-14
references: 12606634
references: J Neurosci Methods. 1980 Dec;3(2):129-49
references: 6110810
references: Biol Psychiatry. 2010 Apr 15;67(8):753-60
references: 20189166
references: Neuroscience. 2010 Apr 28;167(1):11-20
references: 20149847
references: Physiol Behav. 2001 May;73(1-2):229-34
references: 11399316
references: J Neurosci. 2007 Oct 10;27(41):11075-82
references: 17928449
references: Physiol Behav. 2004 Mar;81(1):129-40
references: 15059692
references: J Neurosci Methods. 1996 May;66(1):1-11
references: 8794935
references: Neuroscience. 2001;103(3):777-97
references: 11274794
references: Bioorg Med Chem Lett. 2001 Jul 23;11(14):1907-10
references: 11459658