Harrer M I, Travers S P
Section of Oral Biology, College of Dentistry, Ohio State University, Columbus 43210, USA.
Brain Res. 1996 Mar 4;711(1-2):125-37. doi: 10.1016/0006-8993(95)01410-1.
Fos immunohistochemistry was used to elucidate the pattern of activation elicited by two qualitatively and hedonically distinct taste stimuli, sucrose and quinine, within the first-order gustatory relay, the rostral division of the nucleus of the solitary tract. Compared to unstimulated controls, both sucrose and quinine elicited significant increases in Fos-like immunoreactivity in the rostral central subnucleus, the region of the rostral solitary nucleus that receives the densest primary afferent input. Within the rostral central subnucleus, neurons that exhibited Fos-like immunoreactivity following quinine stimulation were concentrated medially, but neurons that exhibited Fos-like immunoreactivity following sucrose stimulation were distributed more evenly along the mediolateral axis. Despite their differential distribution, sucrose- and quinine-activated neurons also demonstrated notable intermingling. Further, the chemotopic arrangement was only partially consistent with what would be predicted if chemotopy was merely an outcome of orotopy. Our results suggest that a rough chemotopy characterizes the organization of taste responses in the nucleus of the solitary tract, and that the topographic pattern of taste afferent terminations in this nucleus is related to their chemosensitivity as well as to their peripheral spatial distribution.
采用Fos免疫组织化学方法，以阐明在一级味觉传导通路——孤束核吻侧部，由两种性质和愉悦感不同的味觉刺激物蔗糖和奎宁所引发的激活模式。与未受刺激的对照组相比，蔗糖和奎宁均能使吻侧中央亚核（即吻侧孤束核中接受最密集初级传入输入的区域）的Fos样免疫反应性显著增加。在吻侧中央亚核内，奎宁刺激后表现出Fos样免疫反应性的神经元集中在内侧，但蔗糖刺激后表现出Fos样免疫反应性的神经元沿内外侧轴分布更为均匀。尽管它们分布不同，但蔗糖和奎宁激活的神经元也有明显的混合。此外，化学拓扑排列仅部分符合如果化学拓扑仅仅是口腔拓扑结果所预测的情况。我们的结果表明，粗略的化学拓扑表征了孤束核中味觉反应的组织方式，并且该核中味觉传入终末的拓扑模式与其化学敏感性以及外周空间分布有关。
