Ohgushi M, Ifuku H, Ito S, Ogawa H
Department of Sensory and Cognitive Physiology, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Honjo 1-1-1, Kumamoto 860-8556, Japan.
Neurosci Res. 2005 Mar;51(3):253-63. doi: 10.1016/j.neures.2004.11.007. Epub 2004 Dec 29.
The neural activities to sucrose in the reward phase were examined in the primate fronto-operculo-insular and prefrontal cortices during a NaCl-water discrimination GO/NOGO task. Neurons were classified according to the cue-responsiveness into sucrose-specific, cue-differential, or cue-non-differential groups. The onset latencies and decay times divided response temporal patterns into four types. All cue-non-differential neurons were the short latency-short decay type, whereas most sucrose-specific and cue-differential neurons were either the short latency-short decay or short latency-long decay type. Most neurons were histologically located in areas G, 3, and 1-2, the primary gustatory cortices (PGCs), and the precentral operculum, one of the higher-order gustatory cortices (HGCs), whereas a few were in other HGCs, e.g., area 12. Further study of the temporal properties of the neurons in each cortical area revealed two subgroups of short-latency responses with different onset latencies and a group of responses with an intermediate decay time around the boundary between short- and long-decay times in the PGCs. The onset latencies to cues and sucrose were significantly correlated in the HGC, but not in the PGC. These results indicate that different processing mechanisms operate for sucrose in the reward phase in the PGC and HGC.
在一项氯化钠-水辨别“执行/不执行”任务中，研究了灵长类动物额眶岛叶皮质和前额叶皮质在奖励阶段对蔗糖的神经活动。根据线索反应性将神经元分为蔗糖特异性、线索差异或线索无差异组。起始潜伏期和衰减时间将反应时间模式分为四种类型。所有线索无差异神经元均为短潜伏期-短衰减型，而大多数蔗糖特异性和线索差异神经元为短潜伏期-短衰减型或短潜伏期-长衰减型。大多数神经元在组织学上位于G区、3区和1-2区，即主要味觉皮质（PGCs），以及中央前岛盖，即高级味觉皮质（HGCs）之一，而少数位于其他HGCs，如12区。对每个皮质区域神经元时间特性的进一步研究揭示了PGCs中具有不同起始潜伏期的短潜伏期反应的两个亚组，以及一组在短衰减时间和长衰减时间边界附近具有中间衰减时间的反应。在HGC中，线索和蔗糖的起始潜伏期显著相关，但在PGC中不相关。这些结果表明，PGC和HGC在奖励阶段对蔗糖有不同的处理机制。
