Joman Y Natsheh1,2,3,4, Diego Espinoza5, Shaznaan Bhimani5, Michael William Shiflett6. 1. Children's Specialized Hospital Research Center, New Brunswick, NJ, USA. 2. Palestinian Neuroscience Initiative, Al-Quds University, Jerusalem, Palestine. 3. Kessler Foundation, East Hanover, NJ, USA. 4. Departments of Physical Medicine and Rehabilitation, and Neurology, Rutgers, New Jersey Medical School, Newark, NJ, USA. 5. Department of Psychology, Rutgers, The State University of New Jersey, 101 Warren St., 301 Smith Hall, Newark, NJ, 07102, USA. 6. Department of Psychology, Rutgers, The State University of New Jersey, 101 Warren St., 301 Smith Hall, Newark, NJ, 07102, USA. shiflett@rutgers.edu.
Abstract
RATIONALE: Palatability and incentive value influence animal food choice. Dopamine D2/3 receptor signaling may mediate the effects of palatability and incentive value on choice. Dopamine signaling is disrupted in attention-deficit hyperactivity disorder (ADHD). Investigating behavioral choice processes under D2/3 receptor agonists will help elucidate behavioral and pharmacological correlates of ADHD. OBJECTIVES: To determine (1) how changes in incentive value affects choice of actions for outcomes that differ in palatability; (2) the effects of the D2/3 agonist quinpirole on choice based on palatability and incentive value; (3) how choice differs in spontaneously hypertensive rats (SHR; ADHD model) compared with control strains. METHODS: Rats responded instrumentally for two food outcomes (chocolate and grain pellets) that differed in palatability. Following specific satiety of one outcome, rats underwent a choice test. Prior to the choice test, rats were given intra-peritoneal quinpirole (0.01-0.1 mg/kg) body weight. These manipulations were conducted in three strains of rats: SHR rats; the normotensive Wistar-Kyoto (WKY) controls; and Wistar outbred (WIS) controls. RESULTS: All rat strains responded more vigorously for chocolate pellets compared with grain pellets. Quinpirole reduced the effects of palatability and dose-dependently increased the effects of incentive value on choice. SHR rats were the least influenced by incentive value, whereas WKY rats were the least influenced by palatability. CONCLUSIONS: These results show that D2/3 signaling modulates choice based on palatability and incentive value. Disruption of this process in SHR rats may mirror motivational impairments observed in ADHD.
RATIONALE: Palatability and incentive value influence animal food choice. Dopamine D2/3 receptor signaling may mediate the effects of palatability and incentive value on choice. Dopamine signaling is disrupted in attention-deficit hyperactivity disorder (ADHD). Investigating behavioral choice processes under D2/3 receptor agonists will help elucidate behavioral and pharmacological correlates of ADHD. OBJECTIVES: To determine (1) how changes in incentive value affects choice of actions for outcomes that differ in palatability; (2) the effects of the D2/3 agonist quinpirole on choice based on palatability and incentive value; (3) how choice differs in spontaneously hypertensiverats (SHR; ADHD model) compared with control strains. METHODS:Rats responded instrumentally for two food outcomes (chocolate and grain pellets) that differed in palatability. Following specific satiety of one outcome, rats underwent a choice test. Prior to the choice test, rats were given intra-peritoneal quinpirole (0.01-0.1 mg/kg) body weight. These manipulations were conducted in three strains of rats: SHR rats; the normotensive Wistar-Kyoto (WKY) controls; and Wistar outbred (WIS) controls. RESULTS: All rat strains responded more vigorously for chocolate pellets compared with grain pellets. Quinpirole reduced the effects of palatability and dose-dependently increased the effects of incentive value on choice. SHR rats were the least influenced by incentive value, whereas WKY rats were the least influenced by palatability. CONCLUSIONS: These results show that D2/3 signaling modulates choice based on palatability and incentive value. Disruption of this process in SHR rats may mirror motivational impairments observed in ADHD.
Authors: Eduardo Dias-Ferreira; João C Sousa; Irene Melo; Pedro Morgado; Ana R Mesquita; João J Cerqueira; Rui M Costa; Nuno Sousa Journal: Science Date: 2009-07-31 Impact factor: 47.728
Authors: F X Castellanos; J N Giedd; P Eckburg; W L Marsh; A C Vaituzis; D Kaysen; S D Hamburger; J L Rapoport Journal: Am J Psychiatry Date: 1994-12 Impact factor: 18.112