Yamamoto T, Kitamura R
Department of Oral Physiology, Faculty of Dentistry, Osaka University, Japan.
Brain Res. 1990 Mar 5;510(2):309-20. doi: 10.1016/0006-8993(90)91382-q.
The gustatory area was searched in the cerebral cortex of the hamster by means of a combined approach using electrophysiological, behavioral, and histological experiments. The chorda tympani (CT), which innervates taste buds on the anterior part of the tongue, projected to a confined area anterior to the middle cerebral artery and just dorsal to the rhinal fissure. The trigeminal component of the lingual nerve (LN) area was located anterodorsal to the CT area, and the glossopharyngeal nerve (GN), which innervates taste buds on the posterior part of the tongue, was posterior to the CT area. The center of the CT and GN areas belonged to the dorsal part of the dysgranular insular cortex, and the LN area was within the primary somatosensory granular cortex. Bilateral symmetrical ablations of the CT and GN areas abolished the conditioned taste aversion (to sodium saccharin) that had been acquired before ablations, indicating a role of these areas in some cognitive processes of taste perception. Injections of horseradish peroxidase conjugated with wheat germ agglutinin (WGA-HRP) in the CT and GN areas, centered in the dysgranular insular cortex, revealed that this cortical region had major fiber connections with the contralateral homotypical cortical area, ipsilateral amygdala (central, lateral and basolateral nuclei), ipsilateral parvicellular part of the posteromedial ventral nucleus of the thalamus, bilateral parabrachial nucleus, contralateral nucleus of the solitary tract, raphe nuclei, and the locus ceruleus. Conversely, injections of WGA-HRP in these target areas showed anterograde and/or retrograde transport in the similar dysgranular insular cortex and additionally in the ventral part of the granular insular cortex. The present results suggest that the cortical gustatory area of the hamster is about 1.5 X 1.5 mm in size with the topographic organization between anterior and posterior parts of the tongue, and is located mainly in the dysgranular insular cortex around the middle cerebral artery.
通过电生理、行为和组织学实验相结合的方法，在仓鼠的大脑皮层中寻找味觉区域。支配舌前部味蕾的鼓索神经（CT）投射到大脑中动脉前方、紧靠鼻裂背侧的一个局限区域。舌神经（LN）区域的三叉神经成分位于CT区域的前背侧，而支配舌后部味蕾的舌咽神经（GN）位于CT区域的后方。CT和GN区域的中心属于颗粒减少的岛叶皮质的背侧部分，而LN区域位于初级体感颗粒皮质内。对CT和GN区域进行双侧对称切除，消除了切除前获得的对糖精钠的条件性味觉厌恶，表明这些区域在味觉感知的某些认知过程中发挥作用。将与小麦胚芽凝集素结合的辣根过氧化物酶（WGA-HRP）注射到以颗粒减少的岛叶皮质为中心的CT和GN区域，结果显示该皮质区域与对侧同型皮质区域、同侧杏仁核（中央核、外侧核和基底外侧核）、同侧丘脑后内侧腹核的小细胞部分、双侧臂旁核、对侧孤束核、中缝核和蓝斑有主要的纤维连接。相反，在这些靶区域注射WGA-HRP显示在类似的颗粒减少的岛叶皮质以及颗粒岛叶皮质腹侧部分有顺行和/或逆行运输。目前的结果表明，仓鼠的皮质味觉区域大小约为1.5×1.5毫米，具有舌前部和后部之间的拓扑组织，主要位于大脑中动脉周围的颗粒减少的岛叶皮质。
