title: Taste laterality studied by means of umami and salt stimuli: an fMRI study.
abstract: Aim of the present study was to investigate laterality of the gustatory system in the human brain for the taste qualities elicited by MSG (monosodium glutamate) and NaCl (sodium chloride). A total of 23 subjects participated in a block-design functional magnetic resonance imaging (fMRI) study. Liquid stimuli were presented at supra-threshold concentrations and delivered by means of a computer controlled gustometer. Left and right sides of the mouth were stimulated separately in order to correlate statistical parametrical maps to both the site of the stimulus and the specific taste quality. Following the effects of the site of stimulation through primary and secondary gustatory cortices an effort was made to explore the laterality of the gustatory pathways. Our results showed for both tastants a predominance of ipsilateral connections at the thalamus level. Insula left and right regions were both involved for both tastants. In these regions we found a high proportion of ipsilateral connection again for both the tastants. Considering orbitofrontal/prefrontal cortex, left-sided stimulation with NaCl or MSG produced left-sided activation of the orbito-frontal cortex clearly indicating the presence of an ipsilateral path. Finally, the hypothesis of frontal operculum as primary gustatory cortex and lateral prefrontal cortex as secondary was also supported by the results from dynamic causal modeling.
authors.affiliation: Smell & Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School (Technische Universität Dresden), Dresden, Germany. Emilia.Iannilli@uniklinikum-dresden.de
authors.forename: Emilia
authors.initials: E
authors.lastname: Iannilli
authors.forename: P Bano
authors.initials: PB
authors.lastname: Singh
authors.forename: Benno
authors.initials: B
authors.lastname: Schuster
authors.forename: Johannes
authors.initials: J
authors.lastname: Gerber
authors.forename: Thomas
authors.initials: T
authors.lastname: Hummel
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009055:Mouth / Q000187:drug effects* / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology*; D012970:Sodium Glutamate / Q000494:pharmacology*; D013649:Taste / Q000187:drug effects* / Q000502:physiology*; D055697:Taste Perception / Q000502:physiology*
chemical_list: D012965:Sodium Chloride; D012970:Sodium Glutamate