title: Neuronal correlates of appetite regulation in patients with schizophrenia: is there a basis for future appetite dysfunction?
abstract: BACKGROUND
  Given the undesired metabolic side effects of atypical antipsychotic medication it is important to understand the neuronal basis related to processing of appetite regulation in patients affected by schizophrenia.
  
  
  METHODS
  Here we used functional magnetic resonance imaging (fMRI) to assess brain activity in response to food cues and neutral stimuli in twenty patients with schizophrenia and eleven healthy individuals. In addition to clinical and dietary habits assessments, we collected, in patients, measurements of fasting glucose, ghrelin, leptin, insulin, prolactin and lipids blood concentration and we correlated the cerebral activity with clinical and metabolic measures.
  
  
  RESULTS
  Both groups engaged a common neuronal network while processing food cues, which included the left insula, primary sensorimotor areas, and inferior temporal and parietal cortices. Cerebral responses to appetitive stimuli in thalamus, parahippocampus and middle frontal gyri were specific only to schizophrenic patients, with parahippocampal activity related to hunger state and increasing linearly over time. Antipsychotic medication dosage correlated positively with a cognitive measure reflecting food cravings, whereas the severity of the disease correlated negatively with a cognitive measure indicating dietary restraint in eating habits. These cognitive variables correlated, in turn, with parahippocampal and thalamic neuronal activities, respectively.
  
  
  CONCLUSIONS
  We identified a specific neural substrate underlying cognitive processing of appetitive stimuli in schizophrenia, which may contribute to appetite dysfunction via perturbations in processing of homeostatic signals in relation to external stimuli. Our results also suggest that both antipsychotic medication and the disease severity per se could amplify these effects, via different mechanisms and neuronal networks.
authors.affiliation: Departement de psychiatrie, Université de Montréal, Montréal, Québec, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Lungu
authors.forename: K
authors.initials: K
authors.lastname: Anselmo
authors.forename: G
authors.initials: G
authors.lastname: Letourneau
authors.forename: A
authors.initials: A
authors.lastname: Mendrek
authors.forename: B
authors.initials: B
authors.lastname: Stip
authors.forename: O
authors.initials: O
authors.lastname: Lipp
authors.forename: P
authors.initials: P
authors.lastname: Lalonde
authors.forename: L
authors.initials: L
authors.lastname: Ait Bentaleb
authors.forename: E
authors.initials: E
authors.lastname: Stip
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001069:Appetite Regulation / Q000502:physiology*; D001786:Blood Glucose; D001921:Brain / Q000378:metabolism / Q000503:physiopathology*; D001931:Brain Mapping; D003463:Cues; D005260:Female; D005502:Food; D059907:Functional Neuroimaging; D054439:Ghrelin / Q000097:blood; D006801:Humans; D006815:Hunger / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D008055:Lipids / Q000097:blood; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*
chemical_list: D014150:Antipsychotic Agents; D001786:Blood Glucose; D054439:Ghrelin; D007328:Insulin; D020738:Leptin; D008055:Lipids