Neural activities in the fronto-opercular cortex of macaque monkeys during tasting and mastication.
We recorded responses from 298 units in the fronto-opercular cortex (Fop) of three Japanese macaque monkeys. The units were activated while animals were drinking or eating. Three types of units could be defined: units with transient responses to the delivery of all the fluid into the mouth (ON-type units; n = 123); units activated in association with certain oral movements, e.g., licking (MO-type units; n = 90); and units responsive specifically to a certain fluid (taste units; n = 85). In both ON-type and MO-type units were included mechanoreceptive units with receptive fields in the oral cavity, mainly on the tongue and teeth. All but two taste units responded exclusively to gustatory stimuli. ON-type units were found mainly in the precentral opercular area (PrCO), and MO-type units were recorded predominantly in PrCO and area 6. Taste units were concentrated at the gustatory area and at a part of area 1-2. These results indicate the lack of convergence of somatic and taste input on single neurons. In awake monkeys, Fop units of a given function tended to be clustered at certain loci, thereby forming separate functional regions.
Department of Physiology, Kumamoto University Medical School, Japan.
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Ito
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Ogawa
D000818:Animals; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004594:Electrophysiology; D005071:Evoked Potentials; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D008251:Macaca / Q000502:physiology*; D008297:Male; D008409:Mastication / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010812:Physical Stimulation; D013268:Stimulation, Chemical; D013649:Taste / Q000502:physiology*; D014110:Touch / Q000502:physiology