Wild J M
Department of Anatomy, School of Medicine, University of Auckland, New Zealand.
J Comp Neurol. 1993 Dec 8;338(2):225-41. doi: 10.1002/cne.903380207.
The descending, efferent projections of nucleus robustus archistriatalis were investigated in male zebra finches and greenfinches with injections of either biotinylated dextran amine or cholera toxin B-chain conjugated to horseradish peroxidase. The results show that in addition to the well-known projections to the tracheosyringeal motor nucleus and the dorsomedial nucleus of the intercollicular complex, there are other projections of comparable density to the ipsilateral nucleus ambiguus and nucleus retroambigualis. Within nucleus ambiguus, robustus axons terminate in close proximity to laryngeal motoneurons which were retrogradely labelled in the same bird by injections of cholera B-chain into the laryngeal muscles; and within nucleus retroambigualis robustus axons terminate in relation to bulbospinal neurons previously shown to project to regions of spinal cord containing motoneurons innervating abdominal expiratory muscles (J.M. Wild, Brain Res. 606:119-124, 1993). These projections of nucleus robustus thus seem well placed to coordinate syringeal, laryngeal, and expiratory muscle activity during vocalization. Other relatively sparse, but distinct, projections of nucleus robustus were found to nucleus dorsolateralis anterior thalami, pars medialis, to a narrow region between the superior olivary nucleus and the spinal lemniscus, and to the rostral ventrolateral medulla. Neurons in these last two locations were retrogradely labelled bilaterally following injections of cholera B-chain into nucleus retroambigualis of one side. Together with sparse contralateral projections of nucleus robustus to all brainstem targets receiving ipsilateral projections, potential pathways are thus identified by which the respiratory-vocal activity controlled by one side of the lower medulla can be influenced by the nucleus robustus of either side, thereby possibly bringing about bilateral coordination of respiratory-vocal output.
采用生物素化葡聚糖胺或与辣根过氧化物酶偶联的霍乱毒素B链注射法，对雄性斑胸草雀和绿翅金雀中古纹状体粗核的下行传出投射进行了研究。结果表明，除了众所周知的投射到气管鸣管运动核和间丘复合体背内侧核外，还有密度相当的其他投射到同侧疑核和迷走神经后核。在疑核内，粗核轴突终止于喉运动神经元附近，这些喉运动神经元在同一只鸟中通过向喉肌注射霍乱B链而被逆行标记；在迷走神经后核内，粗核轴突相对于先前显示投射到脊髓中含有支配腹部呼气肌运动神经元区域的延髓脊髓神经元而终止（J.M. 怀尔德，《脑研究》606:119 - 124，1993）。因此，古纹状体粗核的这些投射似乎处于很好的位置，能够在发声过程中协调鸣管、喉部和呼气肌的活动。还发现古纹状体粗核有其他相对稀疏但明显的投射到丘脑前背外侧核内侧部、上橄榄核和脊髓丘系之间的一个狭窄区域以及延髓嘴侧腹外侧。在一侧迷走神经后核注射霍乱B链后，这最后两个位置的神经元被双侧逆行标记。连同古纹状体粗核向所有接受同侧投射的脑干靶点的稀疏对侧投射，由此确定了潜在的通路，通过这些通路，由延髓下部一侧控制的呼吸 - 发声活动可受到两侧古纹状体粗核的影响，从而可能实现呼吸 - 发声输出的双侧协调。
