Sykes R M, Spyer K M, Izzo P N
Department of Physiology, University College London, Royal Free Hospital of Medicine, UK.
Brain Res. 1997 Jul 11;762(1-2):1-11. doi: 10.1016/s0006-8993(97)00368-5.
To investigate whether glutamate is a neurotransmitter in vagus nerve sensory afferents terminating in the nucleus tractus solitarius, these terminals were identified by the anterograde transport and their glutamate content examined using the post-embedding immunogold technique. After injection of horseradish peroxidase into the nodose ganglion anterogradely labelled axonal boutons were visualized throughout the nucleus of the solitary tract (nTS), the dorsal motonucleus of the vagus nerve (DVN), predominantly ipsilateral to the injection, and to a lesser extent in the area postrema. Electron microscopic analysis of 47 anterogradely labelled boutons in the nTS following post-embedding immunocytochemistry for glutamate revealed that 43 of these boutons (> 91%) contained a level of glutamate immunoreactivity significantly greater (P < 0.001%) than that observed in the surrounding tissue. The observed enrichment of glutamate immunoreactivity in boutons identified as vagus nerve sensory afferents indicate that glutamate may be a transmitter in these neurones.
为了研究谷氨酸是否是终止于孤束核的迷走神经感觉传入纤维中的神经递质，通过顺行运输鉴定这些终末，并使用包埋后免疫金技术检测其谷氨酸含量。将辣根过氧化物酶注射到结状神经节中后，在整个孤束核（nTS）、迷走神经背运动核（DVN）（主要在注射侧的同侧）以及最后区较小范围内可见顺行标记的轴突终扣。对nTS中47个顺行标记的终扣进行包埋后谷氨酸免疫细胞化学的电子显微镜分析显示，其中43个终扣（>91%）所含的谷氨酸免疫反应性水平显著高于（P<0.001%）周围组织。在被鉴定为迷走神经感觉传入纤维的终扣中观察到的谷氨酸免疫反应性富集表明，谷氨酸可能是这些神经元中的一种递质。
