title: Individual differences in prefrontal cortex activity during perception of bitter taste using fNIRS methodology.
abstract: Although bitter taste has a crucial role in nutrition by preventing the ingestion of toxic foods, there are few studies on bitter taste neuroimaging. To identify cortical areas involved in bitter taste perception and to determine if individual differences in taste sensitivity to 6-n-propylthiouracil (PROP) are represented in the brain by different cortical activation patterns, we examined 48 healthy volunteers using functional near-infrared spectroscopy. Participants rated the perceived intensity of filter paper disks impregnated with PROP and NaCl during the imaging procedure and were then classified as PROP tasters and nontasters. We monitored cortical activity in both the anterior and posterior regions of the dorsolateral prefrontal cortex (DLPFC) and in the ventrolateral prefrontal cortex (VLPFC). No activity was detected in the anterior DLPFC in any of the participants. However, during the administration of PROP, significant cortical activation was detected in the more posterior regions of the left DLPFC and in the left and right VLPFC but only in PROP tasters. PROP nontasters showed no cortical activity in these areas. These data suggest that the prefrontal cortex is involved in the conscious perception of the bitter taste of PROP and that the pattern of activity is consistent with individual differences in the ability to taste this compound. Thus, the PROP phenotype is associated with fundamental differences in cortical taste processing.
authors.affiliation: Department of Reproductive and Developmental Sciences, and Public Medicine Sciences, University of Trieste, via dell'Istria 65/1, 34137 Trieste, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bembich
authors.forename: Carmela
authors.initials: C
authors.lastname: Lanzara
authors.forename: Andrea
authors.initials: A
authors.lastname: Clarici
authors.forename: Sergio
authors.initials: S
authors.lastname: Demarini
authors.forename: Beverly J
authors.initials: BJ
authors.lastname: Tepper
authors.forename: Paolo
authors.initials: P
authors.lastname: Gasparini
authors.forename: Domenico L
authors.initials: DL
authors.lastname: Grasso
mesh_terms: D000328:Adult; D004435:Eating; D005260:Female; D005518:Food Preferences; D006801:Humans; D007206:Individuality; D008297:Male; D010465:Perception / Q000187:drug effects* / Q000502:physiology; D010641:Phenotype; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000502:physiology; D011441:Propylthiouracil / Q000494:pharmacology*; D012965:Sodium Chloride / Q000494:pharmacology*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013649:Taste / Q000187:drug effects* / Q000502:physiology; D013652:Taste Threshold / Q000187:drug effects* / Q000502:physiology; D055815:Young Adult
chemical_list: D012965:Sodium Chloride; D011441:Propylthiouracil