title: Role of NMDA, opioid and dopamine D1 and D2 receptor signaling in the acquisition of a quinine-conditioned flavor avoidance in rats.
abstract: A conditioned flavor preference (CFP) can be produced by pairing a flavor (conditioned stimulus, CS+) with the sweet taste of fructose. Systemic dopamine (DA) D1, D2 and NMDA, but not opioid, receptor antagonists significantly reduce the acquisition of the fructose-CFP. A conditioned flavor avoidance (CFA) can be produced by pairing a CS+flavor with the bitter taste of quinine. To evaluate whether fructose-CFP and quinine-CFA share common neurochemical substrates, the present study determined the systemic effects of DA D1 (SCH23390: SCH), DA D2 (raclopride: RAC), NMDA (MK-801) or opioid (naltrexone: NTX) receptor antagonists on the acquisition of quinine-CFA. In Experiment 1, food-restricted male rats were trained over 8 alternating one-bottle sessions to drink an 8% fructose+0.2% saccharin solution (FS) mixed with one flavor (CS-, e.g., grape) and a different flavor (CS+, e.g., cherry) mixed in a solution (FSQ) containing fructose+saccharin and quinine at 0.001-0.030% concentrations. In six subsequent two-bottle choice tests (1-3: two sessions each) with the CS- and CS+ flavors presented in FS solutions, only rats trained with 0.03% quinine displayed a CS+ avoidance in Test 1. In Experiment 2, rats received vehicle (Veh), SCH (200 nmol/kg), RAC (200 nmol/kg), MK-801 (100 μg/kg) or NTX (1 mg/kg) 30 min prior to the 8 one-bottle training sessions with CS-/FS and CS+/FSQ (0.03% quinine) solutions. An additional vehicle group (Veh 0.06%) was trained with a CS+/FSQ containing 0.06% quinine. In the two-bottle choice tests, the Veh and RAC groups avoided the CS+ flavor in Test 1 only, whereas the SCH, MK801, and NTX groups significantly avoided the CS+ in Tests 1-3. The Veh.06% group trained avoided the CS+ in Tests 1 and 2, but not Test 3. In Experiment 3, Veh and SCH groups were trained as in Experiment 2, but were tested with CS flavors presented in 0.2% saccharin solutions. The SCH group avoided the CS+ flavor in Tests 1-3 while the Veh group avoided the CS+ in Test 1 only. Thus whereas DA D1, DA D2 and NMDA, but not opioid receptor antagonism blocked acquisition of sweet taste-based CFP, DA D1, NMDA and opioid, but not DA D2 receptor antagonism enhanced the CFA produced by the bitter taste of quinine.
authors: Behavioral and Cognitive Neuroscience Cluster of Psychology Doctoral Programs, Graduate Center, City University of New York, New York, NY, United States.
authors: Francis M
authors: FM
authors: Rotella
authors: Department of Psychology, Queens College, City University of New York, New York, NY, United States.
authors: Arzman
authors: A
authors: Badalia
authors: Department of Psychology, Queens College, City University of New York, New York, NY, United States.
authors: Sean M
authors: SM
authors: Duenas
authors: Department of Psychology, Queens College, City University of New York, New York, NY, United States.
authors: Maruf
authors: M
authors: Hossain
authors: Department of Psychology, Queens College, City University of New York, New York, NY, United States.
authors: Shermeen
authors: S
authors: Saeed
authors: Department of Psychology, Brooklyn College, City University of New York, New York, NY, United States.
authors: Khalid
authors: K
authors: Touzani
authors: Department of Psychology, Brooklyn College, City University of New York, New York, NY, United States; Behavioral and Cognitive Neuroscience Cluster of Psychology Doctoral Programs, Graduate Center, City University of New York, New York, NY, United States.
authors: Anthony
authors: A
authors: Sclafani
authors: Behavioral and Cognitive Neuroscience Cluster of Psychology Doctoral Programs, Graduate Center, City University of New York, New York, NY, United States; Department of Psychology, Queens College, City University of New York, New York, NY, United States. Electronic address: richard.bodnar@qc.cuny.edu.
authors: Richard J
authors: RJ
authors: Bodnar
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001552:Benzazepines / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000502:physiology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D065127:Dopamine D2 Receptor Antagonists / Q000494:pharmacology; D005632:Fructose; D008297:Male; D009271:Naltrexone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D011803:Quinine; D020891:Raclopride / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology*; D012439:Saccharin; D015398:Signal Transduction / Q000502:physiology; D013649:Taste / Q000502:physiology*
chemical_list: D001552:Benzazepines; D065127:Dopamine D2 Receptor Antagonists; D009292:Narcotic Antagonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D016194:Receptors, N-Methyl-D-Aspartate; C534628:SCH 23390; D005632:Fructose; D020891:Raclopride; D009271:Naltrexone; D016291:Dizocilpine Maleate; D011803:Quinine; D012439:Saccharin
keywords: Bitter taste; Flavor–flavor avoidance learning; MK-801; Naltrexone; Raclopride; SCH23390; Sweet taste