Conlee J W, Parks T N
Brain Res. 1986 Mar 5;367(1-2):96-113. doi: 10.1016/0006-8993(86)91583-0.
Ascending auditory projections to the nucleus mesencephalicus lateralis pars dorsalis (MLd) were studied in white Leghorn chickens by means of unilateral injections of horseradish peroxidase into the MLd and by injections of tritiated leucine into nucleus angularis or the combined nucleus magnocellularis and nucleus laminaris. The experiments showed that nucleus angularis sends an extensive projection to the contralateral MLd and a smaller projection to the rostral pole of the ipsilateral MLd; the lagenar region contributes to these bilateral connections. Nucleus angularis also projects bilaterally to the superior olive and nucleus ventralis lemnisci lateralis and to the contralateral nucleus lemnisci lateralis pars ventralis and dorsal nucleus of the lateral lemniscus. Projections from nucleus laminaris were demonstrated to the ipsilateral superior olive, to the contralateral lemniscal nuclei and a small medial region in MLd bilaterally; the contralateral projection is much denser than the ipsilateral one. Other nuclei having ascending connections with MLd include the contralateral superior olive, the ipsilateral nucleus lemnisci lateralis pars ventralis, the contralateral nucleus ventralis lemnisci lateralis and the contralateral MLd. The ipsilateral superior olive and nucleus ventralis lemnisci lateralis also project to MLd but much more sparsely than in their contralateral projection. Although several of these findings correspond with auditory connections previously shown in the pigeon brainstem, they differ fundamentally in that we find both nucleus angularis and nucleus laminaris projecting to different areas of the MLd on both sides of the brain. In particular, our observation that the cochlear nucleus has bilateral connections with MLd demonstrates an important avian similarity with the brainstem auditory pathways of other terrestrial vertebrates.
通过向白来航鸡的中脑外侧核背侧部（MLd）单侧注射辣根过氧化物酶，以及向角状核或大细胞核与层状核复合体注射氚标记的亮氨酸，研究了向MLd的听觉上行投射。实验表明，角状核向对侧MLd发出广泛投射，向同侧MLd的吻端发出较小投射；Lagena区域参与了这些双侧连接。角状核还双侧投射到上橄榄核和外侧丘系腹侧核，以及对侧外侧丘系腹侧部核和外侧丘系背核。已证实层状核投射到同侧上橄榄核、对侧丘系核以及双侧MLd中的一个小内侧区域；对侧投射比同侧投射密集得多。与MLd有上行连接的其他核包括对侧上橄榄核、同侧外侧丘系腹侧部核、对侧外侧丘系腹侧核和对侧MLd。同侧上橄榄核和外侧丘系腹侧核也投射到MLd，但比其对侧投射稀疏得多。尽管这些发现中的一些与先前在鸽脑干中显示的听觉连接相对应，但它们在根本上有所不同，因为我们发现角状核和层状核都投射到脑两侧MLd的不同区域。特别是，我们观察到耳蜗核与MLd有双侧连接，这表明鸟类与其他陆生脊椎动物的脑干听觉通路有重要的相似性。
