Matsumoto Ichiro
Monell Chemical Senses Center, Philadelphia, PA 19104, USA.
Biosci Biotechnol Biochem. 2013;77(7):1359-62. doi: 10.1271/bbb.130117. Epub 2013 Jul 7.
Taste receptor cells encounter chemicals in foods and transmit this information to the gustatory neurons, which convey it further to the gustatory relay nuclei in the lower brainstem. Characterizing neurons involved in the transmission of gustatory information in the peripheral and central nervous systems helps us better understand how we perceive and discriminate tastes. However, it is difficult to anatomically identify them. Using cell-type-specific promoters/enhancers and a transneuronal tracer, we generated transgenic mice to visualize neurons in the gustatory neural pathways. We observed the tracer in the neurons of cranial sensory ganglia and the nucleus of the solitary tract in the medulla where gustatory neurons project. The tracer was also distributed in the reticular formation and several motor nuclei in the medulla that have not been recognized as gustatory ascending pathways. These transgenic mice revealed gustatory relay neurons in the known gustatory ascending pathway and an unexpected, thus presumably novel, neural circuit of gustatory system.
味觉感受器细胞接触食物中的化学物质，并将这些信息传递给味觉神经元，味觉神经元再将其进一步传递到脑干下部的味觉中继核。确定参与味觉信息在周围和中枢神经系统中传递的神经元，有助于我们更好地理解我们如何感知和区分味道。然而，从解剖学上识别它们很困难。利用细胞类型特异性启动子/增强子和跨神经元示踪剂，我们培育出转基因小鼠，以可视化味觉神经通路中的神经元。我们在颅感觉神经节的神经元以及延髓中味觉神经元投射的孤束核中观察到了示踪剂。示踪剂还分布在延髓的网状结构和几个运动核中，这些结构尚未被认为是味觉上行通路。这些转基因小鼠揭示了已知味觉上行通路中的味觉中继神经元以及味觉系统中一个意想不到的、因此可能是新的神经回路。
