Hermann G E, Rogers R C
J Auton Nerv Syst. 1985 May;13(1):1-17. doi: 10.1016/0165-1838(85)90002-5.
Our previous anatomical and electrophysiological studies demonstrated that first-order hepatic and gustatory afferents project to separate regions of the solitary nucleus (NST) and no intra-NST interaction of these two sensory systems could be demonstrated. However, iontophoretic injections of horseradish peroxidase into physiologically identified zones of the NST revealed that both of these regions send overlapping projections to the immediately subjacent parvocellular reticular formation as well as the postero-medial parabrachial nucleus (PBN). The present electrophysiological studies demonstrate that an interstitial zone of neurons in the caudal, medial PBN, indeed, receive convergent input from second-order gustatory and vagal afferents. Co-activation of these PBN units by the simultaneous arrival of both input sources frequently resulted in an additive interaction of evoked activity. PBN units lateral and caudal to this zone responded to vagal stimulation only, while units in the anterior and extreme medial portion of the PBN only responded to gustatory stimulation. By virtue of the efferent projections of the PBN, one might speculate that the convergence of information at this locus may, eventually, play a role in directing long term feeding behavior patterns such as learned taste aversion as well as the more transient changes in taste preference with visceral loading.
我们之前的解剖学和电生理学研究表明，一级肝和味觉传入神经投射到孤束核（NST）的不同区域，且未发现这两个感觉系统在孤束核内存在相互作用。然而，将辣根过氧化物酶离子导入法注入经生理学鉴定的孤束核区域，结果显示这两个区域都向紧邻的小细胞网状结构以及臂旁后内侧核（PBN）发出重叠投射。目前的电生理学研究表明，在延髓尾侧、内侧PBN中的一个神经元间质区确实接受来自二级味觉和迷走神经传入神经的汇聚输入。这两种输入源同时到达时对这些PBN神经元的共同激活常常导致诱发活动的相加性相互作用。该区域外侧和尾侧的PBN神经元仅对迷走神经刺激有反应，而PBN前部和最内侧部分的神经元仅对味觉刺激有反应。鉴于PBN的传出投射，人们可能推测在这个位点信息的汇聚最终可能在指导长期进食行为模式中发挥作用，比如习得性味觉厌恶以及随着内脏负荷而发生的更短暂的味觉偏好变化。
