Büttner-Ennever J A, Cohen B, Horn A K, Reisine H
Institute of Neuropathology, University of Munich, Germany.
J Comp Neurol. 1996 Mar 4;366(2):348-59. doi: 10.1002/(SICI)1096-9861(19960304)366:2<348::AID-CNE12>3.0.CO;2-L.
The nucleus of the optic tract (NOT) is associated with the generation of optokinetic nystagmus (OKN), whereas the olivary pretectal nucleus (ol), which lies embedded in the primate NOT, is believed to be essential for the pupillary light reflex. In this anatomical study of the pretectum, projections from NOT and ol to structures around the oculomotor nucleus were traced in the monkey, to determine which cell groups they innervated. 1. 3[H]-leucine injections were placed into NOT and ol, and labelled terminals were observed just outside the classical oculomotor nucleus (nIII), in the "C-group' and midline cell clusters, both of which contain small motoneurons of the extraocular eye muscles. In addition, there were strong projections to the lateral visceral cell column of the Edinger-Westphal complex (lvc), but not to the Edinger-Westphal nucleus (EW) itself. All of these projections were mainly contralateral. 2. NOT efferents terminated over the ipsilateral medial accessory nucleus of Bechterew (nB), but not over the adjacent nucleus Darkschewitsch. 3. Injections of a retrograde tracer into the oculomotor complex showed that the pretectal afferents described above originated mainly from the dorsomedial part of NOT and from ol. 4. The use of a transsynaptic retrograde tracer, tetanus toxin fragment (BIIb), established the monosynaptic nature of the connection between dorsomedial NOT (contralaterally) and ol (bilaterally), to the small extraocular motoneurons outside classical nIII. The "C-group' motoneurons may play a role in vergence, and lvc in pupillary constriction and depth of focus. Our results imply that NOT and ol participate in the control of some aspects of the near-response, which may be important in the generation of some components of OKN in primates.
视束核（NOT）与视动性眼震（OKN）的产生有关，而埋于灵长类动物视束核内的橄榄前顶盖核（ol）被认为对瞳孔光反射至关重要。在这项对顶盖前区的解剖学研究中，在猴子身上追踪了从视束核和橄榄前顶盖核到动眼神经核周围结构的投射，以确定它们支配哪些细胞群。1. 将³H-亮氨酸注射到视束核和橄榄前顶盖核中，在经典动眼神经核（nIII）外侧的“C组”和中线细胞簇中观察到标记的终末，这两组均含有眼外肌的小型运动神经元。此外，有强烈的投射至动眼神经副核复合体的外侧内脏细胞柱（lvc），但未投射至动眼神经副核（EW）本身。所有这些投射主要是对侧性的。2. 视束核传出纤维终止于同侧的贝切特列夫内侧副核（nB），但未终止于相邻的达克谢维奇核。3. 向动眼神经复合体注射逆行示踪剂表明，上述顶盖前区传入纤维主要起源于视束核的背内侧部分和橄榄前顶盖核。4. 使用跨突触逆行示踪剂破伤风毒素片段（BIIb）证实了视束核背内侧部分（对侧）与橄榄前顶盖核（双侧）与经典nIII外侧的小型眼外肌运动神经元之间连接的单突触性质。“C组”运动神经元可能在辐辏中起作用，而lvc在瞳孔收缩和焦点深度方面起作用。我们的结果表明，视束核和橄榄前顶盖核参与了近反射某些方面的控制，这在灵长类动物OKN某些成分的产生中可能很重要。
