title: Prefrontal cortex modulates desire and dread generated by nucleus accumbens glutamate disruption.
abstract: BACKGROUND
  Corticolimbic circuits, including direct projections from prefrontal cortex to nucleus accumbens (NAc), permit top-down control of intense motivations generated by subcortical circuits. In rats, localized disruptions of glutamate signaling within medial shell of NAc generate desire or dread, anatomically organized along a rostrocaudal gradient analogous to a limbic keyboard. At rostral locations in shell, these disruptions generate appetitive eating, but at caudal locations the disruptions generate progressively fearful behaviors (distress vocalizations, escape attempts, and antipredator reactions). Here, we asked whether medial prefrontal cortex can modulate intense motivations generated by subcortical NAc disruptions.
  
  
  METHODS
  We used simultaneous microinjections in medial prefrontal cortex regions and in NAc shell to examine whether the desire or dread generated by NAc shell disruptions is modulated by activation/inhibition of three specific regions of prefrontal cortex: medial orbitofrontal cortex, infralimbic cortex (homologous to area 25 or subgenual anterior cingulate in the human), or prelimbic cortex (midventral anterior cingulate).
  
  
  RESULTS
  We found that activation of medial orbitofrontal cortex biased intense bivalent motivation in an appetitive direction by amplifying generation of eating behavior by middle to caudal NAc disruptions, without altering fear. In contrast, activation of infralimbic prefrontal cortex powerfully and generally suppressed both appetitive eating and fearful behaviors generated by NAc shell disruptions.
  
  
  CONCLUSIONS
  These results suggest that corticolimbic projections from discrete prefrontal regions can either bias motivational valence or generally suppress subcortically generated intense motivations of desire or fear.
authors.affiliation: Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA. jocelyri@umich.edu
authors.forename: Jocelyn M
authors.initials: JM
authors.lastname: Richard
authors.forename: Kent C
authors.initials: KC
authors.lastname: Berridge
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D001640:Bicuculline / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000502:physiology*; D008297:Male; D008845:Microinjections; D009042:Motivation / Q000187:drug effects / Q000502:physiology*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors
chemical_list: D018691:Excitatory Amino Acid Antagonists; D058787:GABA-A Receptor Antagonists; D011810:Quinoxalines; D018091:Receptors, AMPA; D018698:Glutamic Acid; C056723:FG 9041; D001640:Bicuculline