title: Deep brain stimulation in the central nucleus of the amygdala decreases 'wanting' and 'liking' of food rewards.
abstract: We investigated the potential of deep brain stimulation (DBS) in the central nucleus of the amygdala (CeA) in rats to modulate functional reward mechanisms. The CeA is the major output of the amygdala with direct connections to the hypothalamus and gustatory brainstem, and indirect connections with the nucleus accumbens. Further, the CeA has been shown to be involved in learning, emotional integration, reward processing, and regulation of feeding. We hypothesized that DBS, which is used to treat movement disorders and other brain dysfunctions, might block reward motivation. In rats performing a lever-pressing task to obtain sugar pellet rewards, we stimulated the CeA and control structures, and compared stimulation parameters. During CeA stimulation, animals stopped working for rewards and rejected freely available rewards. Taste reactivity testing during DBS exposed aversive reactions to normally liked sucrose tastes and even more aversive taste reactions to normally disliked quinine tastes. Interestingly, given the opportunity, animals implanted in the CeA would self-stimulate with 500 ms trains of stimulation at the same frequency and current parameters as continuous stimulation that would stop reward acquisition. Neural recordings during DBS showed that CeA neurons were still active and uncovered inhibitory-excitatory patterns after each stimulus pulse indicating possible entrainment of the neural firing with DBS. In summary, DBS modulation of CeA may effectively usurp normal neural activity patterns to create an 'information lesion' that not only decreased motivational 'wanting' of food rewards, but also blocked 'liking' of rewards.
authors.affiliation: Biomedical Engineering Department, Ann Arbor, MI, USA.
authors.forename: Shani E
authors.identifier: 0000-0001-7305-3451
authors.initials: SE
authors.lastname: Ross
authors.affiliation: Department of Neurosurgery, Ann Arbor, MI, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Lehmann Levin
authors.affiliation: Neuroscience Graduate Program, Ann Arbor, MI, USA.
authors.forename: Christy A
authors.identifier: 0000-0002-6740-5577
authors.initials: CA
authors.lastname: Itoga
authors.affiliation: Department of Psychology, 530 Church Street, Ann Arbor, MI, 48109-1043, USA.
authors.forename: Chelsea B
authors.initials: CB
authors.lastname: Schoen
authors.affiliation: Department of Psychology, 530 Church Street, Ann Arbor, MI, 48109-1043, USA.|Department of Biology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Romeissa
authors.initials: R
authors.lastname: Selmane
authors.affiliation: Department of Neurosurgery, Ann Arbor, MI, USA. jwaynea@umich.edu.|Department of Psychology, 530 Church Street, Ann Arbor, MI, 48109-1043, USA. jwaynea@umich.edu.
authors.forename: J Wayne
authors.initials: JW
authors.lastname: Aldridge
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D066274:Central Amygdaloid Nucleus / Q000502:physiology*; D046690:Deep Brain Stimulation; D005247:Feeding Behavior / Q000502:physiology; D005502:Food; D005518:Food Preferences / Q000502:physiology*; D008297:Male; D009042:Motivation / Q000502:physiology*; D009714:Nucleus Accumbens / Q000502:physiology; D017207:Rats, Sprague-Dawley; D012201:Reward
keywords: food reward; neural recordings; operant responding; rat; taste reactivity