Neuroscientific studies on brain mechanisms of affective behavior, learning and memory of taste.

本研究的目的是揭示味觉刺激激活的脑内物质，并显示这些物质对大鼠神经元反应性的可塑性变化。这项人体实验旨在通过非侵入性脑成像技术揭示大脑对味觉质量的处理以及味觉的享乐性评估。结果表明：1)味觉偏好学习的脑机制：在苍白球腹侧注射多巴胺D_1受体拮抗剂或谷氨酰胺受体拮抗剂可减少糖精摄取，而阿片受体拮抗剂可增加糖精摄取。2)微透析研究：奎宁可增加脑组织胺的释放，而蔗糖或糖精不能促进组胺的释放，表明组胺的释放与厌恶味觉有关。3)味觉厌恶学习的脑机制：注射荷包牡丹碱，GABA受体拮抗剂，4)非侵入性脑成像研究：当提供匹配的气味和视觉图像时，大脑对气味和视觉图像的同时模拟的磁性反应比不匹配时更大。

The purpose of the present research project was to reveal brain substances activated by taste stimuli and to show plastic changes of responsiveness of neurons by those substances in rats. The experiments on humans aims to disclose brain functions about taste quality processing and hedonic evaluation of taste with the use of non-invasive brain imaging techniques. The following results were obtained :1)Brain mechanisms of taste preference learning : Injections of a dopamine D1 receptor antagonist or a glutamine receptor antagonist into the ventral pallidum decreased saccharin intake, while a opioid receptor antagonist increased saccharin intake.2)Microdialysis study : Brain histamine release was increased by quinine, but no release by sucrose or saccharin, indicating that histamine release was related aversive taste.3)Brain mechanisms of taste aversion learning : Injections of bicuculline, GABA receptor antagonist, into the ventral pallidum in the rat trained to reject saccharin attenuated aversions to saccharin.4)Non-invasive brain imaging study : Magnetic response of the brain was greater to simultaneous simulation of odor and visual image when delivered matched than mismatched.