抄録
Several gustatory cortices have been identified in macaque monkeys: primary gustatory cortices (PGC: areas G and 3), adjacent cortices (area 1-2 and insula), and higher-order gustatory cortices (HGC) including the precentral opercular (PrCO), orbitofrontal opercular (OFO), and orbitofrontal cortices (areas 12 and 13). To investigate coding mechanism of taste perception, we examined neural activities in the PGC and HGC in the monkey during a salt-water discrimination GO/NOGO task. Most neurons differentially responded to two cues, salt and water. In the reaction time task, the onset latency in the exposed frontal operculum (area 3 and the PrCO) was distributed with two modes, each at short and long latencies, but neurons in the buried part (area G and insula), OFO, and orbitofrontal cortices had long latencies, suggesting different roles of two cortical groups in the task. Analysis in the incidental incorrect trials revealed that some neurons in the HGC yielded activities related to subsequent behavioral responses. In the delayed task and its reversal, the PGC almost exclusively contained neurons signaling the physicochemical nature of the cues and the HGC contained neurons related to the subsequent behavior, attention or short-term memory, as well. Thus, it is indicated that the PGC processes pure gustatory information, whereas the HGC are involved in gustatory perception and other higher-order function. [Jpn J Physiol 54 Suppl:S19 (2004)]
