Miyaoka Y, Shingai T, Takahashi Y, Yamada Y
Department of Physiology, Niigata University School of Dentistry, Japan.
Neurosci Res. 1997 Jul;28(3):201-7. doi: 10.1016/s0168-0102(97)00044-8.
Responses of parabrachial nucleus (PBN) neurons (n = 43) to chemical stimulation of the posterior tongue were recorded in chorda tympani (CT)-sectioned rats and compared with those (n = 45) in CT-intact. The chemical stimuli used were 0.5 M sucrose, 0.5 M sodium chloride (NaCl), 0.03 M hydrochloric acid (HCl), 0.01 M quinine hydrochloride, and distilled water. These stimuli were applied to an area posterior to the intermolar eminence of the tongue. Neurons of CT-sectioned rats responsive to the chemical stimuli were located in more caudal areas of the PBN compared with those of CT-intact. Numbers of responses to the five stimuli and breadth of responsiveness to the four basics were not different between both groups of rats. However, average response magnitudes of the neurons in CT-sectioned rats were lower than those in CT-intact. In both groups of rats, the response magnitudes to NaCl and HCl were larger than those to the other three stimuli, and responses to NaCl and those to HCl were highly correlated. It is suggested that glossopharyngeal fibers responding strongly to acids and salts are likely to be the main source of PBN responses from the posterior tongue.
在切断鼓索神经（CT）的大鼠中记录了臂旁核（PBN）神经元（n = 43）对舌后部化学刺激的反应，并与完整CT的大鼠（n = 45）进行了比较。所使用的化学刺激物为0.5M蔗糖、0.5M氯化钠（NaCl）、0.03M盐酸（HCl）、0.01M盐酸奎宁和蒸馏水。这些刺激物施加于舌磨牙间隆起后方的区域。与完整CT的大鼠相比，切断CT的大鼠中对化学刺激有反应的神经元位于PBN更靠尾侧的区域。两组大鼠对五种刺激的反应次数以及对四种基本刺激的反应广度没有差异。然而，切断CT的大鼠中神经元的平均反应幅度低于完整CT的大鼠。在两组大鼠中，对NaCl和HCl的反应幅度大于对其他三种刺激的反应幅度，并且对NaCl和对HCl的反应高度相关。提示对酸和盐有强烈反应的舌咽纤维可能是PBN来自舌后部反应的主要来源。
