title: Neural ensemble coding of satiety states.
abstract: The motivation to start or terminate a meal involves the continual updating of information on current body status by central gustatory and reward systems. Previous electrophysiological and neuroimaging investigations revealed region-specific decreases in activity as the subject's state transitions from hunger to satiety. By implanting bundles of microelectrodes in the lateral hypothalamus, orbitofrontal cortex, insular cortex, and amygdala of hungry rats that voluntarily eat to satiety, we have measured the behavior of neuronal populations through the different phases of a complete feeding cycle (hunger-satiety-hunger). Our data show that while most satiety-sensitive units preferentially responded to a unique hunger phase within a cycle, neuronal populations integrated single-unit information in order to reflect the animal's motivational state across the entire cycle, with higher activity levels during the hunger phases. This distributed population code might constitute a neural mechanism underlying meal initiation under different metabolic states.
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA. arujo@neuro.duke.edu
authors.forename: Ivan E
authors.initials: IE
authors.lastname: de Araujo
authors.forename: Ranier
authors.initials: R
authors.lastname: Gutierrez
authors.forename: Albino J
authors.initials: AJ
authors.lastname: Oliveira-Maia
authors.forename: Antonio
authors.initials: A
authors.lastname: Pereira
authors.forename: Miguel A L
authors.initials: MA
authors.lastname: Nicolelis
authors.forename: Sidney A
authors.initials: SA
authors.lastname: Simon
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000204:Activity Cycles / Q000502:physiology; D000818:Animals; D001522:Behavior, Animal; D001786:Blood Glucose; D001921:Brain / Q000166:cytology; D001931:Brain Mapping; D005247:Feeding Behavior / Q000502:physiology; D007328:Insulin / Q000097:blood; D008297:Male; D009474:Neurons / Q000145:classification* / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012527:Satiation / Q000502:physiology*; D013649:Taste / Q000502:physiology; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin